Research Methods I

1/3 of research methods

Whats a variable?

A construct: Something that can vary

What are variables in psychology?

1. Behaviour or cognitive processes themselves

2. Factors that influence/cause said behaviours or cognitive processes

What is an independent variable (IV)?

Factors in a study which researchers manipulate to see effects
(cause)

What is a dependent variable (DV)

Factors in a study which researchers measure
(effect)

Affect definition

verb: to influence/change something

Effect definition

Noun: the consequence/result caused by an action

What is the aim of any experiment?

See what effect an IV has on a DV

What is an extraneous variable (EV)?

Factors that might affect the results

What are examples of EV's?

1. Participant variability

2. Order effects

3. Participant expectancy

What are confounding variables?

EV's that actually affect the results

What is a control?

Something that you do to minimize the possibility that EV's can affect results

What are the characteristics of true experiments?

1. Take place in controlled environments where researchers control EV's

2. Researchers create different conditions (random allocation)

3. IV causes the change in DV

treatment group

Receives treatment that is hypothesized to have an affect (manipulation of the IV)

Control group

Receives no treatment or one that is designed not to have any effect

What is placebo?

A treatment that is designed to have no effect

What is a correlation?

A correlation indicates that as one variable changes, the other variable also changes. No causation is implied

What is a positive correlation?

Change for both variables happens in the same direction

What is a negative correlation?

Change for both variables happens in opposite directions

What is bidirectional ambiguity?

When direction of a relationship between two variables isn't clear

What are spurious correlations?

When two variables appear to be correlated but it is clearly due to either chance or another unseen factor

Are all causal relations also correlations?

yes

how are true experiments used in cognitive psychology?

True experiments in cognitive psychology sometimes manipulate an IV that is hypothesized to affect cognition
EV's are controlled for the IV to be the only factor affecting the DV

Why are true experiments used in cognitive psychology?

If we know what factors affect cognition and how, we explain cognitive processes

What is the purpose for experimental designs and controls?

To limit EV's as much as possible to make clearer cause-effect relationships and increase validity of the data

What do experimental designs do?

Determine how participants experience the conditions of the experiment:

1. Independent samples

2. Repeated measures

3. Matched pairs

What are independent samples?

When participants are randomly assigned to groups, experience only one condition of the experiment

Pros of independent samples

Random allocation allows us to control EV's such as:

1. Participant expectancy effect: when they suspect aim/results and alter their behaviour

2. Order effects: When doing more than one task, the order in which they are presented can affect the result

Cons of independent samples

Participant variability: differences in participants could influence results

What are repeated measures?

all participants experience all conditions of the experiment

Pros of repeated measures

Limits participant variability and does not require as many participants

Cons of repeated measures

Potential order effects (can be controlled through counterbalancing)
Higher chance for participant expectancy effect

What are matched pairs?

Participants matched from some relevant criteria and allocated to different conditions

Pros of matched pairs

Allows to control potential hidden biases/ EV's that can skew results
Limits participant variability

Cons of matched pairs

Harder to run/ design
May affect the value of randomization as selection bias could happen

What is a risk possible for all three experimental designs?

Potential researcher bias: researchers can unconciously interpret results differently or give unwanted cues to participants according to their experimental group. Can be controlled by:

1. single-blind design

2. double-blind design

What is a single blind design?

When the participant doesn't know which group they belong to

What is a double-blind design?

When neither the participant nor the researcher know which group they belong to

What is the overall benefit of controls and experimental designs?

It increases the internal validity of the experiment

What is internal validity?

The extent to which the evidence found actually supports a cause-effect claim.

What is a field experiment?

Manipulation of an IV and measurement of the effect of a DV in a naturalistic setting

How do field experiments work in social psychology?

IV is often a social factor
Researchers manipulate the IV and see effects on behaviour by comparing results across groups
We want to see how people act in real-life situations

What is ecological validity?

how well can findings of research be generalized to real-world, everyday settings

What are the differences between field and true experiments?

Field experiments have high ecological validity which give more realistic findings
Field experiments cannot control for many EV's
Field experiments causality is less cleary established

What is a quasi-experiment?

When there is the study of an IV on a DV to establish causality, but one or more defining conditions of a true experiment cannot be met

When are quasi-experiments useful?

when not all conditions of a true experiment can be met due to ethical or practical reasons

What is a natural experiment?

An experiment where the IV is naturally occuring (researchers cannot manipulate it)

What experiments are types of quasi-experiments?

natural and field experiments are quasi-experiments

How does a correlational study differ from an experiment?

• Variables measured without manipulation

• Goal is not to establish causality but to explore association between variables

• High in external validity

What is external validity?

The extent which findings of a study could be applied to other people, settings, situations and timeframes

What are the three 'categories' of external validity?

1. Population validity

2. Ecological validity

3. Temporal validity

What is population validity?

The extent which findings could be generalized to other groups of people with different characteristics

Temporal validity

The extent which findings could apply to different time eras

Correlation coefficients

1.0: means there is a perfect positive correlation between two variables. (the closer to 1, the stronger the positive correlation)
-1.0: means there is a perfect negative correlation between two variables (closer to -1 , stronger negative correlation)

What does is mean when the correlation coefficient =0?

variables aren't correlated at all

What is the most commly used correlation coefficient?

Pearson’s R

What is a case study?

• Investigation of a person or small group

• Usually conducted over a long period of time

• Uses range of different methods (quantitative and qualitative) to gather a lot of data

Why are case studies valuable, but hard to replicate?

• Valuable bc can explore highly unique situations that would be impossible to study

• Hard to replicate bc of ehtical concerns

What is a human/social science?

a branch of academic study that focuses on human behavior, society, and relationships

What is a phenomenon?

an observable, reliable pattern of human behavior or mental process that has been documented through empirical research