Lecture 1

Question 1

What’s an independent variable ?

Answer 1

Variable that’s manipulated by the experimenter

Question 2

What’s a dependent variable?

Answer 2

Outcome variable which is affected by the manipulated variable

Question 3

What are the levels of independent variable?

Answer 3

IV has many different levels
general dimension being manipulation, the levels of the variable are the various conditions

Question 4

A study is examining whether caffeine affects memory performance.
Participants are randomly assigned to consume either 0mg, 25mg, 50mg,
75mg, or 100mg of caffeine, and then their memory performance is assesse

Answer 4

Dependent variable: memory performance
• Independent variable: amount of caffeine consumed
• Levels of the independent variable – 5: 0mg, 25mg, 50mg, 75mg, and 100mg

Question 5

What’s extraneous variable?

Answer 5

Variables that have potential to affect dependent variable

Question 6

What’s a confounding variable?

Answer 6

If an extraneous variable changes systematically with your independent
variable, then this is a confounding variable

Question 7

Why is it important to establish cause and
effect?

Answer 7

• important to understand relationship between different things
  Has lots of applied relevance

Question 8

What does correlation not equal?

Answer 8

Causation

Question 9

What does Anderson argue about demonstrating cause and effect?

Answer 9

Examined data on violent crimes in north America and found the hotter the year the more violent crimes, showing how hate causes aggression

Question 10

What might have been other factors in Anderson’s study?

Answer 10

More people outside
Alcohol used

Question 11

What did rule et al argue?

Answer 11

Randomly allocated participants to a 21°C or 33°C room.
Participant were asked to complete stories, some of which had an
ambiguous ending which could have been aggressive or non-aggressive.
• Participants in the hot condition produced significantly more aggression in the
ambiguous ending condition that did participants in the cool condition.

Question 12

Describe a true experiment?

Answer 12

Manipulates an independent variable
• Holds all other variables (i.e. extraneous variables) constant
• Measures any change in the dependent variable

Question 13

Why are control groups used?

Answer 13

• If you want to see how a treatment or intervention has affected an
outcome then you need to know what the outcome would be without
the treatment.
• Many studies use a control group to give a baseline measure of what
would have without the treatment

Question 14

What’s the placebo effect?

Answer 14

an inert substance or treatment that doesn’t contain any
active ingredients.

Question 15

What does a placebo allow us to do ?

Answer 15

Allows us to see whether the effects of a treatment are due to
participants expectations of an effect.

Question 16

Strengths of true experiment?

Answer 16

• Can isolate cause and effect relationships between the independent variable
and the dependent variable
• Can control extraneous variables
• Easy to replicate and modify/extend

Question 17

Weakness of true experiments?

Answer 17

Not always possible/practical to manipulate the independent variable
• Can sometime be artificial
• Reactivity effects – participants react differently to normal as they know they
are in an experiment
• Participants cannot give their personal account of their behaviour

Question 18

What’s quasi experimental?

Answer 18

When particpants aren’t randomly allocated

Question 19

What are the diff types of simple experimental designs?

Answer 19

• Independent samples design
• Repeated measures design
• Matched pairs
• Single participant and small N

Question 20

Explain the independent sample design?

Answer 20

• characteristics of the particpants that might influence the results
• ## there may be differences in partipants characteristics between our groups

Question 21

Whats a weakness of the independent sample design?

Answer 21

That there might be differences in characterises between the groups which we may not know if it’s due to the changes in our dependent variables to the indepdent variable

Question 22

Whats the controlling for participants variables in independent sample designs?

Answer 22

• random allocation
• pre-test for participants
  -representative allocation

Question 23

What are some repeated measures design?

Answer 23

• control and elimate differences is by having one group do all conditions
• differences between partipants become irrelevant
• within subject designs

Question 24

What does within subject designs mean ?

Answer 24

Same measure is repeated in each participant under various conditions of the independent variable

Question 25

How is a related measure design different from multiple testing?

Answer 25

- repeated measures involves the same dependent variable under different conditions • Multiple testing involves using multiple tests but without repetitio

Question 26

Example of how repeated measures involves design is different to multiple testing?

Answer 26

Repeated measures • Glucose levels (DV) are measured before after consuming a snack (IV) • Not repeated measures • Glucose levels (1st DV) and blood pressure (2nd DV) are measured after consuming a snac

Question 27

Main disadvantage of repeated measures design?

Answer 27

Order effects - the order in which you complete the conditions affects the results It’s important to control effects through counterbalancing

Question 28

Disadvantages of independent samples?

Answer 28

Non-equivalence of samples • More expensive • Homogeneity of variance

Question 29

Disadvantages of repeated measures?

Answer 29

Order effects • Loosing participants • Experimenter demands • Need to wait until the effects wear of

Question 30

Should you use independent samples or repeated measures

Answer 30

- generally better to use repeated measures design as it reduces variability in the sample

Question 31

In what instances are independent samples more better to be used then repeated samples?

Answer 31

- not practical, ethical for participants to be assigned more then one conditions - order effects can’t be eliminated or are asymmetrical - Particpants need to be naive for each condition - when control groups is needed

Question 32

Whats matched pairs?

Answer 32

• A method in which subjects are allocated to their groups (experimental or control) “matched” on a variable that may confound the interpretation • Making sure that the groups are equal on one or more variables before the experiment starts. • Can weaken result if the matching variable isn’t correlated with the dependent variable

Question 33

Whats small n designs?

Answer 33

- Using one participant across multiple conditions • Examples of this might be for populations that are extremely small or difficult to recruit, e.g. participants will particular types of brain injury. • Other examples might be where there is very prolonged periods of testing or training.

Question 34

Whats multifactorial designs?

Answer 34

Effects of more than one independent variable on a dependent variable, and their interaction. • Example: A study is examining whether smoking affects lung performance more in males than females. Independent variable 1: smoker status (smoker vs. non-smoker); independent variable 2: sex (females vs. males); dependent variable: lung performance

Question 35

Advantages of online experiments?

Answer 35

Can be conducted even if face-to-face testing is not possible (during a pandemic, for example!) • Can easily and quickly recruit large number of participants • Possible to recruit a more diverse range of participant

Question 36

Disadvantages of online experiments?

Answer 36

Not practical for research questions that involve physically different conditions (e.g. hot or cold rooms, ingesting a substance) • Difficult to conduct if specialist equipment is required (e.g. eye tracking) • Lack of control over what participants are doing • Technical difficulties