Experimental versus non experimental design

2 Mar

Today in class we reviewed different types of experimental and non-experimental studies.

What make an experiment, an experiment?  What is random assignment? What is a longitudinal study or case study?

Then I offered the class the following questions and they formed into groups and selected one.  How would they design a study to answer the question?

1) DO BLONDS HAVE MORE FUN?

2) DOES SUNSHINE LEAD TO HAPPINESS?

3) DOES LACK OF SLEEP INFLUENCE STRESS LEVELS?

4) DOES EXERCISE LEAD TO WEIGHT LOSS?

HOMEWORK ASSIGNMENT 4: Select one of these questions that you did not address in your group.  Design a study to answer the question.

a) Is your study a real experiment? Why or why not?

b) What are limitation to your study?

c) How do  you propose obtain consent for your study?

d) What are potential confounds in your study? What do you propose to do about these?

Post your answers here. Come to class on Tuesday ready to tell us about your study!

19 Responses to “Experimental versus non experimental design”

  1. Carissa Boncardo March 7, 2011 at 3:51 am #

    DOES EXERCISE LEAD TO WEIGHT LOSS?

    In order to preform this experiment, I would have two groups of one hundred subjects, fifty men and fifty women in each group, who are randomly assigned. Diet would be controlled for in the study as would how much each person exercises per day. Group 1 would be required to exercise for a designated amount of time per week, and Group 2 would be limited to the changed diet. Each participant would be given a pedometer to track their number of steps per day in order to control for that as well. The type of exercise would also be important to note, and could potentially call for a third group since cardio and weight-bearing offer different effects.

    a) My study is a real experiment because I am manipulating the variable of amount of time per week a participant spends exercising. I am seeking to observe whether or not exercising causes weight loss.

    b) The limitations to our study are the participants themselves. Because they will not be held in a research facility for the time of experimentation, we will have to depend on the participants to keep true to the limitations of the study. However, with a large sample and the short amount of time of a month (which could be extended depending on the willingness of the participants), the results should produce significant data.

    c) I propose obtaining consent for my study by informing the participants of what the diet will contain, the amount and intensity of exercise they will be required to do, and what will be expected for them to disclose during the duration of the study.

    d) Potential confounds of the study will be the diet issue and the differing body types of the participants. In some cases, a modified diet alone will help certain participants lose weight. To control for this confound, a period of time before the exercising starts could be given where the participants’ bodies have time to get used to the new diet. With the differing body type confound, the larger number of participants should be able to control for this.

  2. Andriy Mokritski March 7, 2011 at 8:48 pm #

    In class my group and I designed an experiment to test whether sunshine leads to happiness. Here I would like to discuss another experiment more practical and somewhat obvious.

    Does exercise lead to weight loss?

    Our independent variable is exercise and dependent variable is weight loss. We would randomly select 200 people consisting of 100 males and 100 females of various ages, races and athletic capabilities. Two groups will be formed randomly assigning people to each group. Group I will be placed on a specific exercise regiment including cardio, weight lifting and aerobics 2 hours a day, 4 times a week and will be closely monitored for a period of 3 months. Group II instead of exercising will be watching movies 2 hours a day, 4 times a week and will be closely monitored for a period of 3 months. Both groups will be placed on the same daily diet.

    a) Our study design is a true experiment because we randomly assigned participants and manipulated the independent variable.
    b) The limitations of our experiment will mostly be narrowed down to the participants. Everyone has a different body type and some may lose weight faster than others. During 22 hours of the day where people are by themselves some can cheat on their diets. Even though exercise in itself will be closely supervised, some participants might work harder at it than others. Bad habits such as smoking and alcohol consumption, as well as stress may affect the amount of weigh lost.
    c) All participants will be informed of the study design. Since a large and growing percentage of our population is obese, I do not believe that it will be a problem getting consent from participants.
    d) The confounds of this study will include the will of the participants to follow the diet and exercise routines, in which we can help by positive reinforcement and encouragement. Everyday life stressors which we cannot be controlled. In addition, since everyone’s bodies are different participants may lose weight differently. We can try to correct this by designing individual exercise routines and diets, but that would complicate the study and add limitations. Larger sample size and longer experiments will narrow the confounds.

  3. Norbert Futeran March 7, 2011 at 10:40 pm #

    I would conduct the experiment of trying to see if diet effects wait loss. To conduct this experiment i would randomly assign 200 people into two different groups. Group 1 would be the exercise group and group two would be the group that does not exercise. Both groups will have a mandatory high protien diet plan and will have the same sleep schedule to try and limit confounds in the study. The only difference between the groups will be that group 1 has to go to the gym for at least 1 hour a day, while group 2 is not allowed any exercise during the experiment.

    1) My study is a real experiment because I have two randomly assigned groups in which I will be manipulating one variable while keeping all others properties equal in both groups. Finally I will attempt to measure if exercise does have an significant effect on weight loss

    2)The limitations to my study is that it is impossible to watch 400 people and make sure they hold up their end of the agreements and go to the gym for at least one hour a day and stay on a diet that everyone has to stay on.

    3) I propose to inform all participants on the details of the study and inform them of the risks/benefits of the study and how it can benefit them long term. Assuming that most people who sign up for the program will be overweight or just unhappy with their weight they will also have the benefit of self motivation because they have an opportunity to lose the weight they had been hoping for.

    4)The confound in my study is other factors that can lead to weight gain or just weight that wont be shed due to high levels of stress at work or just high levels of stress in general. Another confound in my study is that different people’s bodies respond differently to the diet plans they are on and to the amount of work the need to put in in order to actually lose weight. In terms of controlling stress we can have all participants undergo stress releasing exercises to help them relax and always feel comfortable during the study. As for body type and how they react to the diet and exercise is really something you cant control too well and would have to change your exercise and diet plan to suit the person specifically and this will create even more confounding variables.

  4. Christine Luebcke March 7, 2011 at 11:12 pm #

    DOES EXERCISE LEAD TO WEIGHT LOSS?
    In order to conduct this experiment, I would have two groups of 200 people, 100 men and 100 women in each group. Each group will be randomly assigned so there is no error within the study. The participants would have to be controlled on what they eat and how they exercise. Group 1 would be assigned specific exercises and will also have to remain on the same diet as group 2 who is not exercising. Group 2 would be have the changed diet. Each participant would be weighed in before and after the study to test if weight loss is present.

    a) This is a real experiment because there is manipulation of variables. The food and exercise is changed for each group and there is also a control to make sure each group follows by the same criteria.

    b) The limitations to the study are the participants in the experiment. The only way we can test them is observing what they do when they are in front of us for the study. We wont be able to control what they do outside of the study and if they actually follow the diet outside of the study area.

    c) I would obtain consent for my study by allowing the participants to know the criteria of what the exercise and diet will be. They will also be informed of the criteria of the study and what rules they must follow and how long it will last.

    d) Potential confounds of the study will be the food each participant eats and the different ways their body reacts to those foods and exercises given. Not all participants will have the same body type or cardio to keep up with the exercises so the results will vary. In some participant a diet without exercise could cause weight loss, but on the other hand some people need to exercise a lot in order to seek results. To control for this confound, the exercising could be simple and the diets could be simple as well so all participants can be equal and the results could be produced to the best ability. starts could be given where the participants’ bodies have time to get used to the new diet. The more people in the study the better the results will be to propose if exercise helps weight loss.

  5. David Chung March 7, 2011 at 11:14 pm #

    Do blonds have more fun?

    For this study, I would use 60 female participants. 20 would be naturally red haired, 20 naturally black haired and 20 naturally brunette. Each group of 20 would have equal amounts of different age groups. All 60 participants would participate in 4 activities which include playing volleyball, hanging out at a bar, going to a nightclub and doing community service. After each activity participants will fill out survey testing how much they enjoyed activity and how much fun they had doing it. When all data is compiled all 60 participants will change their hair color blond. Participants can choose to be fitted with wigs or actually dye their hair blond. All participants will repeat the same activities and fill out same surveys. Control group for this experiment will be the participants data with original hair color and experimental group will be participants data with blond hair color.

    A) This study is a real experiment because the variable of hair color in participants is being manipulated and natural hair color is being changed to blond.

    B) Limitations of the study are that males are not being studied for this experiment and therefore these results cannot be generalized to the whole population of blonds. Also these participants are not natural blonds and therefore natural blonds may have different experiences from those in our study.

    C) I would obtain consent for this study by creating a consent form that informs participants that they are free to leave the study at any time, that they may choose to dye their hair or to just wear a wig and that their participation in this study is voluntary.

    D) One confounding variable for this study is that participants may have a better time or have more fun with an activity if they are familiar with it or have done it once before. So participants doing the same activity a second time may have more fun not because of their hair color but because they are familiar with it. One way to fix this confounding variable is to start half the participants as blonds with wigs and then let them do the activities again with their natural hair color.

  6. Emily Mercado March 7, 2011 at 11:45 pm #

    Does lack of sleep contribute to stress level?

    In order to perform this experiment, I would have 200 (100 men and 100 women) subjects and 5 groups. Each group would contain 40 people who would be randomly assigned into 1/5 groups.

    Group 1 = 8 hours of sleep
    Group 2 = 10 hours of sleep
    Group 3 = 6 hours of sleep
    Group 4 = 4 hours of sleep
    Group 5 = Regular sleep schedule

    The study would take place for 7 days.

    Sleeping would have to take place in a lab setting to make sure that the participants are sleeping for the designated amount of time. During the day, they would be allowed to do their regular routines and would then have to come back at a designated time to sleep.

    Before beginning the experiment, each participant would be surveyed to determine their stress level. At the end of the procedure, they would be surveyed again to determine whether their stress rose or fell according to the amount of sleep they obtained.

    A. I believe this would be a real experiment since I’m manipulating the variable of sleep levels.

    B. Limitations to this study include:
    a. Are the participants actually achieving the desired hours of sleep – people take different amounts of time to fall asleep. At what point do you begin measuring – is there a way to find out when the participant actually falls asleep
    b. Being able to trust that the participants are not changing anything else about their daily routines besides their nighttime sleep patterns.

    C. I plan to obtain consent by explaining to possible participants the benefits and risks of the experiment. I also would want to let them know that they can drop out at any time without feeling guilty and without repercussion. I would also explain that the group they would be assigned to is completely random.

    D. Possible confounds include:
    a. Is the lab setting affecting stress levels
    i. Some people feel more comfortable sleeping at home. Solution: Maybe I would have to screen for people who don’t mind sleeping away from home. Or I could design the room to feel more “homey”.
    ii. Commute from lab setting to everyday activities could be longer or shorter than the participants are accustomed to and could affect stress. Solution: Measure sleep patterns at home – this could be an invasion of privacy though.
    b. Many things contribute to stress such as diet and sex life – could these be controlled?
    c. Are the participants taking naps during the day – would this be something I would have to control?

  7. minelis arias March 8, 2011 at 12:58 am #

    DOES EXERCISE LEAD TO WEIGHT LOSS ?

    For this experiment I would randomly assign 50 people and then divide them into two distinct groups of 25. One group would be the non-exercise group (control group), while the other group would have to exercise for approximately 2 hours a day. Both groups would have to consume the same quality and quantity of food. These two groups would be under observation for a period of 4 weeks. At the end of each completed week, the two groups’ weight loss or gain would be monitored by using a scale.
    a) Is your study a real experiment? Why or why not? This experiment would be a real experiment because it has a control group which are untreated subjects who are used to determine whether the exercise (independent variable) leads to weight loss (dependent variable) on the experimental group.
    b) What are limitation to your study? A limitation would be the participant consistency. Not being around the participants to know whether they are keeping their side of the bargain, that is consuming the same quantity and quality of foods as everyone else.
    c) How do you propose obtain consent for your study? Consent would consist of giving each subject detailed information about the experiment, ensuring that they want to participate. Also I would have to make sure that no one would be harmed in the study, referring back to my knowledge about ethics and how the advantages should out way the disadvantages.
    d) What are potential confounds in your study? What do you propose to do about these? Women and men are know to have differing body types with women having more fat due to hormone regulation and child bearing. Women may not lose as much weight as men so the women in the experiment would have to try a slightly varied diet differing from the men’s diet.

  8. Stella March 8, 2011 at 12:58 am #

    Does exercise lead to weight loss?
    Experimental hypothesis: Exercise leads to weight loss
    For this study there will be two groups tested, a random sample of 200 people, 100 male, 100 female for each group. Diet has to be the same for everyone. One group will be exercising daily for one hour for one week, preferably at the same time each day. Weight will be recorded at the beginning of the week and daily, and on the last day as well. The second group will do little to no exercise at all; weight will be recorded in the same way.
    a) this is a true experiment because the participants are chosen at random and also the variable are being manipulated. The control is that everyone is on the same diet, and the amount of exercise is manipulated.
    b) Limitations are that not every body is the same for example metabolism. We cannot have accurate data unless participants are observed and watched while they exercise or if participants already regularly exercise on their own.
    c) I will provide a form for participants to sign letting them know the amount and type of exercise required. Also the types of food they will be eating for a week. Letting participants know that this can benefit them in the long run if the study turns out that exercise does help weight loss.
    d) Some potential confounds are the participants body type is different, some may lose weight faster than others. The diet might not be as appetizing to all participants. There are other variables to when weight is loss or gained for example stress levels and their psychological well being. There might be another way to test for weight loss, using the same participants for both the variables of not exercising and exercising.

  9. Fatmah Ghadban March 8, 2011 at 3:04 am #

    Does Exercise lead to weight loss?

    To perform this experiment, I would have 200 people; 100 males and 100 females, and randomly assign them into 2 different groups. The first group would be the group that does not exercise and the second group will be the group that does exercise. I will control this experiment by having both groups follow the same diet and start that diet at the same time. Group 2 will b exercising for an hour everyday for 2 weeks. I would test each participant’s weight before we manipulate anything as well as at the end of the experiment to see if we notice a difference between those who exercise to those that don’t.

    a) This is a real experiment because I am manipulating which group gets exercise and which doesn’t. At the same time I am controlling the fact that each group is on the same diet.

    b) Limitations are that by randomly assigning each participant to a group, we will have to trust the fact that they are following the study and not sneaking food outside of their diet or that group 2 is actually exercising and not pretending.

    c) I will obtain consent for my study by explaining to the participants that this is a voluntary study and I will tell them what the diet consists of and I will urge them to agree to this experiment if they are almost positive that they are going to stay until the end so that there is no room for error if at any point they decide they don’t want to continue with the study.

    d) Potential confounds would be the diet and the metabolism rate of the participants. Not everyone’s body is the same and so depending on that, some people may just need the diet to lose weight while others that exercise and are on a diet still may not lose as much weight as those just dieting. Other potential confounds could be that there are other factors contributing to the weight loss such as stressful events, not enough sleep etc…

  10. Ancy A. March 8, 2011 at 3:10 am #

    DOES LACK OF SLEEP INFLUENCE STRESS LEVELS?
    Design:
    A sample of 300 people, 150 male and 150 female, of the same or similar job backgrounds and professions, i.e. hospital care, business, politics, academia, with similar diets.
    They will be then be randomly divided into 5 groups. The groups will be as follows:
    Group 1: 9 hours of sleep*
    Group 2: 7.5 hours of sleep*
    Group 3: 6 hours of sleep*
    Group 4: 4.5 hours of sleep*
    Group 5: 3 hours of sleep*
    *Designated hours are based on circadian rhythms = 5 cycles of sleep consisting of 90 minute intervals.
    The study would take place for 3 days, because anything after that will harm the person in terms of health, and may lead to death in extreme cases.
    The subjects will commence with their normal activates for the durations of the ‘daytime’ during the 3 days of study, but will return to the laboratory to actually sleep. This is to control that the subjects are actually sleeping. In all instances, at the designated sleep times, the person’s rooms will be simulated to darkness to allow the brain to see the darkness as a signal of nighttime/sleep. If those in groups of less sleep are unable to stay up, they will be allowed to entertain themselves in any way to simulate their brains, but will not be given any caffeine as such might affect stress levels.
    There will be a Pre-Stress Test that will consist of a survey stress test incorporating other questions, as well as a cardiac stress test, as well as other measures, including, heart rate, insulin levels, etc. After the study, the same tests will be repeated, and appropriate statistical tests will be conducted.

    A. This experiment design is a real experiment because I am manipulating the variable of sleeping time.
    B. Limitations to this study may include the following: empirical studies that show different people need different hours of sleep. Randomizing the sampling and grouping might help, but it may still provide people who are able to perform their normal work with only 3 hours of sleep, and those that might need exactly 8 hours of sleep to get up in the morning. I hope that stress levels will however, remain indicative of less sleep. There is also the issue of when the person actually falls asleep. A common phenomenon is that many may remain awake in their beds and not sleep the allotted number of hours. In addition, the fact that the sleep occurs in an unfamiliar place may influence how much sleep the person actually gets, and if that might add to some of their stress levels.
    C. I propose to obtain consent for my study, first presenting to the IRB and gaining IRB approval. In addition, a consent form as well as a verbal explanation will include information about what the study entail and its randomization of grouping but will not include what the study is measuring. (it is found that subjects might want to please the researcher by providing answers to obtain researcher approval). Subjects will be notified of their ability to remove themselves from the experiment at any times, as well as the notification of possible, however slight, health risks. After the study, subjects will be debriefed and provided with psychological care in case any of their reported/measures stress levels were dangerous.
    D. Confound include: the stress of being away from their families adding to the stress being measured. Other activities that may add to stress levels that may not be measured. For instance, while subjects are instructed to do normail daily activites, certain days might just be stressful that others owing to family problems, commute, job problems, etc. It would be very difficult to control for all of those aspects.

  11. Arielle Zieff March 8, 2011 at 3:25 am #

    Does Exercise lead to weight loss?
    In order to conduct this experiment, there must be two groups being tested. There will be a sample of 300 people. 150 male and 150 female for each group. Group 1 would be the group that exercises each day and group 2 will not exercise at all. Group one will spend 2 hours a day at the gym for a month, 6 days a week. Both groups will have the same diet, as well as sleep patterns.

    1. My study is a real experiment because the groups are being chosen at random and the variables are being manipulated. The amount of exercise each group gets is what is being manipulated and the control is the exercise group.
    2. Limitations are that not everybody may be used to exercising this much, so they might be injured. Another limitation is that metabolisms are different. Some people in the group might have participated in a sport so their metabolism is faster than the others, who have never played a sport or exercised in their life.
    3. In order to inform my participants of the study, I will provide a consent form, letting them know the risks, and what they are entitled to do. I will propose an exercise regimen, an example of a diet as well as the recommended amount of sleep necessary to perform.
    4.Potential confounds would be some of the participants aren’t sleeping as much as they should be and in conclusion, their body might not be reacting the same way as the person who sleeps an adequate amount. Many people may not be happy with the diet, and deviate from what is recommended which can be a negative confound. The last confound is metabolism, which is also seen as a limitation.

  12. Karla Rubio March 8, 2011 at 3:48 am #

    Does Exercise lead to Weight loss?
    In my study I would have two groups made of 100 men and 100 women. We would weigh each participant before the study. One group, randomly selected would come in to the lab for an hour to do the treadmill at any time of the day, to increase the variability in participants. The other group comes into the lab for an hour to sit and read a book or watch some television for an hour. After a month we weigh the individuals in both groups to determine if the exercise made a difference.
    This is a real experiment because I am manipulating the variable of amount of exercise in each individual.
    Limitations include different fat percentages among individuals, differences in metabolism, maybe participants are exercising on their own at other times of the day when they are not supposed to. Perhaps they can not make it in one of these days for an hour.
    Consent forms will be provided with risks and benefits detailed. They will be awarded a free gym memberhip at the Ny Sports Club if they come in for their hour everyday.
    SOme potential confounds that can happen are that some may develop health issues or get sick and not be able to come in for a day. Some may have thyroid problems that may not allow them to lose weight like the average person. THe food intake is also a confound, perhaps some participants are overly eating because they think they are compensating with exercise.

  13. Karen Fong March 8, 2011 at 4:03 am #

    DOES SUNSHINE LEAD TO HAPPINESS?

    For this experiment I would survey 100 participants who regularly go to the beach in the summer and survey the same participants in the winter. Summer is when the sun is blazing and winter is when people normally stay at home to stay warm. Studies show that light does affect a person’s mood positively, so finding whether there is a contrast in a person’s mood between the summer and winter might help find a significant result in whether sunshine makes a person happy.

    a) My study is a not a real experiment, because I am not physically manipulating the independent variable, which in this case is season. I am simply measuring the same participants in two naturally occuring conditions.

    b)There are a few limitations to this study. I am following the same participants for at least 6 months to obtain results, therefore it is hard to gather data from all 100 participants when I survey them in the second setting. It is hard to contact all 100 participants and some may drop out of the study or even forget about that they agreed to a survey.

    c)I would first need to obtain IRB Consent by providing a detailed description of my study. After approval, I would need to obtain consent from participants. For this I would provide consent forms and their bill of rights, informing them that this study is anonymous, that their identity would be hidden. I would use codes to substitute the participants’ names. They would also know that they have the right to drop out of the study anytime.

    d)Potential confounds include: One, it may not be sunshine that makes people happy but the thought of summer and all the activities that associate with this season that makes people happy. Two, it may be that people are usually working during the winter that makes them less happy than they are in summer. The cold weather keeps people indoors therefore there are fewer leisure activities for them to engage in.

  14. Cindy Bonilla March 8, 2011 at 5:02 am #

    Does lack of sleep influence stress levels?
    Experiment:
    I will have a sample size of n=400 people. 100 people will sleep for 8 hours, 100 people will sleep for 5 hours, 100 people will sleep for 3 hours, and 100 people will have 1 hour of sleep. These would be the daily counts. The test will run for one week. The same amount of people in each group would have the same jobs to perform daily. They would all eat the same things, so food won’t be a cause for stress. The participants could retrieve themselves from the experiment at any time, especially if it might harm the body. They are chosen from different socio-cultural backgrounds, genders, ages, economic statuses, and employment statuses. Their cortisol level, heartbeat, and blood pressure will be measured three times a day.
    1. Yes, my project is a real experiment. The independent variable is the amount of time each person will sleep. The time will be manipulated as follows; 8 hours of sleep, 5 hours, 3 hours, and 1 hour.

    2. Not being able to control all factors that affect stress is a limitation to the project. Studies show that certain cultures are more prone to experiencing stress than others. We also know that women have a higher stress ratio in comparison to men. It is also known that people deal with stress differently, and that your personality has a lot to do with your coping skills.

    3. I propose to inform the participants on the pros and cons of this study. I will tell them how this study will help us teach people on stress, and how sleep deprivation may have an effect in our systems. I will inform them that they may leave the study at any time. And that if at any point this project affects their health, they will be removed. They will also be told about the length, and the diet they must be under.

    4. A confound is that people deal with stress differently. Higher stress levels could be found due to their backgrounds before the study. To avoid this we could use a matched subjects design to experiments. It’s when people with the same characteristics are placed in different groups and tested.

  15. Aneta Bujno March 8, 2011 at 5:27 am #

    Work it Girl: Do Blondes Have more Fun?

    For the participants, we generalize hair color into three definitive groups (that include all various shades in that group): Blondes, Redheads, and Brunettes. The participants range from ages 18- 30. This sample only includes females. The ethnicity range and socioeconomic status is varied. 300 participants in all; 100 to each definitive group. What is the independent variable? Hair Color. What is the dependent variable? The amount of fun. The dependent variable will be analyzed according to a questionnaire after three activities that we engage every participant in. The three activities involve swinging on a swing, dancing, and put into a “flirting” interaction with hired actors. Do Blondes have more fun than women of other hair colors?

    Each activity will have a questionnaire at its’ conclusion. These questionnaires will be designed to measure different levels of “fun”, operationalizationed by the three activities. The combined score on these three questionnaires will serve as the dependent variable.

    If blonde women have significantly higher scores on the “fun” measures than those of other women, our hypothesis will be supported.

    1. Yes, we have an identified independent and dependent variable. The independent variable is manipulated. We have a representative sample and used random sampling. We used a convenient sample of the Upper East Side due to limited resources.

    2. The limitations of this study include the limited representative sample of the Upper East Side of Manhattan, NY, how effectively the survey accurately measures “fun”; the age range is also somewhat limited to young women.

    3. Get an approved consent form by the IRB. Hand it to the participant before the experiment begins. Only with their written consent will they be allowed to participate.

    4. A confound could be that the multicultural sample is not diversified enough. The culture is somewhat restricted to a very limited culture of the Upper East Side, a socioeconomically well off neighborhood.

  16. Milana Babayeva March 8, 2011 at 5:36 am #

    Does exercise lead to weight loss?
    For this study, I would randomly assign 100 participants to the experimental group (those that will exercise) and 100 participants to the control group (those who will not exercise). All participants would be in the same age range and from the same state. In each group, there will be an equal number of females to males. All the participants will be on the same diet and have similar working and sleeping schedules. The participants from the exercise group will exercise an hour a day for four days a week, for a total of six months. Each participant will be weighed every week.
    1) The study is a real experiment because it is looking to find a cause and effect relationship. We want to see if exercise causes weight loss.
    2)The limitations of the study is that we will not be able to accurately know if the participants are keeping to their diet plans. In addition, many participants can be going through stress or other factors that may effect their diet and weight.
    3)I will ask the participants to sign a consent form that will include all details of the study, such as diet and exercise plans. I will also make sure to include that they can withdraw from the study whenever they please.
    4)Potential confounds include specific health issues that many participants may have that may affect their exercise and weight loss abilities. Body type, metabolism, and sleeping patterns can skew the results of the study as well.

  17. Artem Prober March 8, 2011 at 1:55 pm #

    I would choose the experiment of the effect of exercise on weight loss. I would start with a randomly selected group of 200 participants and split them evenly into an exercise group and a non exercise group. To eliminate some other factors that may lead to weight loss I would have to make sure both groups have the same diet. The exercise group would be limited to cardio (3 miles every other day) and calastatics. Absolutely no weight training would be allowed, weight training can lead to some weight gain as muscles grow. The non exercise group will not exercise at all.

    1) This is a real experiment because my groups are randomly selected. While manipulating one variable (exercise) I will try to keep all the other variables the same for both groups. In this experiment I will measure if exercise had a significant effect on weight loss.

    2) The limitations that I will come across in this study are the size off the population. It is much harder to keep track of 200 participants. I would need a few observers to help me keep track and make sure the exercise group actually goes to thee gym, and to make sure both groups stick to the diet. Another limitation that I might come across is peoples metabolism. Even though a diet might help regulate metabolism, not everyone body works the same.

    3) Information on the risks and benefits will be provided to each participant. I will also provide a flyer on how important exercise is to good health. With the consent forms I will provide the diet outline that is mandatory and the amount if exercise that is required.

    4) Not everyone has the same outcomes when losing weight, it is hard to control hormones and body abilities. That is my biggest confound. That includes reaction to the diet. For some a diet is enough for weight loss. A larger sample of people might help eliminate this confound.

  18. Stephanny Vizuete March 8, 2011 at 2:19 pm #

          DOES EXERCISE LEAD TO WEIGHT LOSS?
    I would have two groups of one hundred subjects, fifty women and fifty male in each group, who are randomly assigned. We will control for the diet an time they eat as well as how much each person exercises per day. Group 1 would be required to exercise for a specific amount of time each day for two weeks, and Group 2 would exercise three times a day during the same time. 
    a) My study is a real experiment because I am manipulating the variable of amount of time a participant spends exercising.
    b) The limitations to our study are the participants since they burn fat at different rates and they have different body types. However, with a large sample and the short amount of time  I should get a significant data.
    c) I propose obtaining consent for my study by informing the participants of what the diet will contain and at what time they will have to eat it. The intensity, days and amount of exercise participants will be required to do. I will info them that they can leave the experiment went they want.
    d) Potential confounds of the study will be the different body types of the participants.  I will weight the participants before and after to make sure to control for this. Another confound I found is the age of my participants. I will divided my groups in gender and age.

  19. karen Del Carpio March 8, 2011 at 7:20 pm #

    DOES EXERCISE LEAD TO WEIGHT LOSS?

    For this study, there would be two groups of 100 subjects recruited, randomly assigned to intervention and control group. Participants will be between the ages of 21 to 29. Group 1 will be assigned to a vigorous intensive physical routine. The second group will be assigned to a non strict exercise routine. The subjects in the experimental group would be seen by a dietician who will control their weights. This study will take about one year. This is a real experiment because we are dealing with people who will be manipulated, exposed to a treatment and we will be observing the causes and effects. Some of the limitation in this study would be participant’s personal emotional state. The particular responses of the participants to their routines may be influenced by his or her emotional states. Emotional states such as: stress, low self-esteem and depression, etc. Bias sources which the research has not control at all. The participants previous to sign the consent form would be explained about their privacy, about the possibility of withdrawing from the study at any time. Confounds in this study will include participant’s health issues and metabolism.

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