Experimental Design Questions

Question 1

State the 10 things needed to create an experimental design

Answer 1

1. Hypothesis and prediction
2. Control
3. IV and DV
4. How IV and DV are manipulated/measured
5. Hold other variables constant
6. Replicates (sample size)
7. Experiment to be repeated
8. Awareness that one can never prove a hypothesis
9. Ethics
10. Confounding effects/bias

Question 2

Create an experimental design to test the claim that Ginkgo Biloba supplements improve memory

Answer 2

1. Hypothesis: if individuals take the Ginkgo biloba supplements over a span of 3-4 months then they will show improved memory performance.
   Prediction: individuals taking the supplements will perform better on the memory tests given than those taking a placebo after 3-4 months
2. Control(s): The group receiving a placebo with the nonactive supplement will be compared to the non placebo group. Conduct the experiment in the same environment for both groups
3. IV: The supplements (placebo vs GB)
   DV: Memory performance on the tests based off of questions and skills that require the use of memory
4. Use random assignment to place participants in either the GB or control group and administer memory tests before and after taking the supplements. The tests will be scored to show the performance of each individual before and after
5. Hold variables such as age as constant as possible and the lifestyles such as sleep and diet of the participants should be closely matched with each other. Use the same testing condition for all participants
6. Aim for a large sample size of 100 participants so 50 in each group. This would help get more accurate and reliable data because of the large sample size
7. Repeat the experiment with different age groups (teens, adults) to gain a deeper understanding about the supplements
8. The hypothesis above can never be proven so more study and experiments should be done to further support the hypothesis
9. Inform the participants about risks, purpose, procedure of the supplements and make sure the experiment is approved by the ethics board and constantly monitor the participants taking GB
10. Other factors that could occur could be education background, poor lifestyle choices and stress levels that all affect memory
    Bias reduction: double blind study to increase the validity of a study by helping minimize Experimenter and participant bias

Question 3

Design a study to test the claim that creatine supplements improve muscle mass during strength training

Answer 3

1. Hypothesis: If an individual takes creatine supplements to improve muscle mass during strength training then their muscle mass will significantly increase compared to a placebo over a span of 3-4 months
   Prediction: individuals taking the supplement will show increased muscle mass after that period of time
2. Control: have a group control taking a placebo pill that does not contain creatine and have both groups follow the same training program
3. IV: the supplements (Creatine vs Placebo)
   DV: The gain of muscle mass
4. IV will be manipulated by giving the control and experimental group 3-4 grams of the supplements daily
   Muscle mass will be measured at the beginning of the training program, half way through the training program and at the end of the training program
5. Hold the variables such as diet and training constant
6. Replicates: have a large sample size of at least 100 people for 50 in each group
7. Repeat the experiment with multiple populations, genders and age to further explore the effects of the supplement
8. It should be acknowledged that the hypothesis can never be proven so more study and research needs to be done
9. Inform all participants of the risks and symptoms of the drug and regularly monitor them
   Get the experiment approved by the ethics board
10. Confounding effects: genetics, previous training experience are effects
    Use double blind experiment

Question 4

Design a study to test the claim that green tea consumption decrease cancer

Answer 4

1. Hypothesis: if individuals intake green tea on a regular basis of around 6 months than the incidence of cancer can be decreased in the population
   Prediction: participants consuming green tea will lead to a lower incidence of cancer
2. Control: participants should not be active green tea drinkers. A control group will not be given green tea. Participants must have similar lifestyles
3. IV: Frequency and quantity of green tea consumption
   DV: incidence of cancer
4. IV and DV manipulated/ measures
   IV: one group will be randomly assigned green tea and the other no green tea
   DV will be measured through regular medical checkups and health questionnaires throughout the stufy
5. Hold the diet, physical activity and lifestyle choices constant. Participants should be given strict guidelines about their diet and lifestyles
6. Replicates: aim for a large size to get a good representative of the entire population so 1000 people with 500 in each group
7. Experiment should be repeated with different ethnic groups and ages
8. Be aware that the hypothesis can never be proven so more study and research is required
9. Inform participants about the risks and procedure and about the strict guidelines they have to follow. Get experiment approved by the websites board
   Confounding variables: genetics, environmental/job exposures and pre existing health conditions
   Bias prevention: a double blind experiment

Question 5

Design a study to test the claim that fiver consumption decreases the incidence of colon cancer

Answer 5

1. Hypothesis: increase driver consumption significantly decreases the incidence of colon cancer
   Prediction: individuals taking in more Fiber will show a lower incidence of colon cancer diagnosis
2. Control: have a control group and put them on a lower fibre diet
3. IV: intake of fiber
   DV: incidence of colon cancerr
4. IV manipulated by putting groups on either high or low fibre diets
   DV will be measured through regular medical checkups and self health questionairres
5. Hold variables such as diet and physical activity constant for both groups
6. Replicate size: have a large sample size of about 1000-12000 participants to get a good range
7. Experiment needs to be repeated with different ethnic groups and ages
8. Hypothesis can not be proven
9. Inform participants and ethics board
10. Confounding effects: genetics and pre existing health conditions + environmental exposure

Double blind study

Question 6

Design a study to test the claim that exposure to parasites (hookworm) prevents the development of multiple sclerosis

Answer 6

1. Hypothesis: exposure to hookworms reduced the incidence of multiple sclerosis in individuals
   Prediction: individuals exposed to hookworms will show a lower incidence of MS compared to those not exposed over a long period of 5-6 years.
2. Control: participants that are as closely matched to each other will not receive hookworm exposure
   Expose the experimental group to the larvae in a controlled environment
3. IV: exposure to hookworms
   DV: incidence of MS
4. IV is manipulated by giving one group no exposure and the group a lot of exposure
   Measurement of DV: assessed through clinical and medical checkups

Hold variables such as family history and age constant and also monitor lifestyle factors

Aim for a large sample size

Experiment should be repeated

Awareness that one can never prove a hypothesis

Ethics: should be approved by ethics board

Confounding effects: environment, genetic
Use double blind procedure and random assignment