Experiments

Question 1

Name all types of experimental methods

Answer 1

Lab, Field, Natural, Quasi

Question 2

Explain Lab experiment (strengths and weaknesses)

Answer 2

Experiment is conducted under controlled conditions, researcher deliberately changes something in IV to affect DV so it has higher internal validity.

Strengths = control & replicable.

weaknesses = lacks ecological validity

Question 3

Explain Field experiment (strengths and weaknesses)

Answer 3

These experiments are carried out in a natural setting, in which the researcher manipulates something (I.V.) to see the effect of this on something else (D.V.).

Strengths = good validity

weaknesses = less control so more extraneous variables

Question 4

Explain Natural experiments (strengths and weaknesses)

Answer 4

Conducted in the everyday (i.e. real life) environment of the participants, but here the experimenter has no control over the independent variable as it occurs naturally in real life.

Strengths = high ecological validity ( behavior in a natural experiment is more likely to reflect real life because of its natural setting ) and no demand characteristics.

Weaknesses = Expensive and no control so extraneous variables may occur.

Question 5

Explain demand characteristics .

Answer 5

When a participant gains characteristics because they guess what the experiment entails, they then try to alter their traits and match these of what the experiment needs.

Question 6

What is IV and DV ?

Answer 6

IV = factor that is directly manipulated by researcher in order to test its effect on DV

DV = factor measured by researcher

Question 7

Hypothesis must be operationalise the variables, what does this mean ?

Answer 7

State how IV is manipulated and how the DV will be measured.

Question 8

What are the three types of hypothesis ?

Answer 8

Null, One tailed alternative (directional), Two tailed alternative (non - directional)

Question 9

Explain Null hypothesis

Answer 9

Predicts no difference between conditions or no correlation between groups. States results are due because of chance alone.

Question 10

Explain One tailed (directional) hypothesis

Answer 10

Predicts there will be a difference between two conditions or correlation and states the direction of the difference. EG group A will have higher score than group B

Question 11

Explain two tailed (non - directional) hypothesis

Answer 11

Predicts there will be a difference between two conditions or correlation but doesn’t state direction of the difference. EG The score between groups A and B will be different.

Question 12

Explain difference between Non-directional and Directional hypothesis

Answer 12

Non - directional = no past research or past research is contradictory.

Directional = Past research suggests findings will go in particular direction.

Question 13

What does a good hypothesis contain ?

Answer 13

Dv and how it’ll be measured, Iv and how it’ll be manipulated …. (operationalising variables) and what the psychologist expects to find.

Question 14

What are the two types of variables that can interfere with results ?

Answer 14

Extraneous variable, Confounding variable

Question 15

What is extraneous variable, What is confounding variable ?

Answer 15

Extraneous = variables that may affect DV [ reduce validity ]

Confounding = variables that HAVE affected DV [ reduce validity ]

Question 16

Name the 3 types of experimental designs.

Answer 16

independent groups, Repeated measures and matched pairs.

Question 17

Explain Independent groups and give limitations / how to deal with them.

Answer 17

Participants placed in separate groups EG Group A does test with Tv on and group B does test with Tv off then compare DV.
Limitations:
- researcher can’t control participant variable (height etc) people in one group might have better memory.
- needs a lot of participants

Dealing with this:
- randomly allocate participants to conditions trying best to distribute variables.

Question 18

Explain repeated measures and give limitations / how to deal with them.

Answer 18

[2 groups] All participants do test once then do it again later experiencing all of IV equally. EG Group 1 and 2 does test A then 3 weeks later does test B, then compare the results between the tests.

Limitations:

• Order effect (boredom / anxiety / stress) could occur second time round.
• When participants do the second test they know the aim.

Dealing with this:

• Counterbalancing (Reshuffle tests); EG Group 1 does test A then test B however group 2 does test B then test A (ABBA)
• Cover main idea of the tests

Question 19

Explain matched pairs and give limitations / how to deal with them.

Answer 19

Use 2 groups and match key characteristics believed to affect performance on Dv.
- One member of each pair allocated to each group and then rest of experiment takes place like “independent groups”
Limitations:
- Very time consuming to find people who have matching characteristics
- Can only match suitable variables EG Could do a memory test but one person could have had memory booster classes
Dealing with this:
- restrict number of variables needed to match
- pilot study to consider key variables ( test run )