IB Psychology - Research methods

What is the difference between causation and correlation in psychology? What are the four main parts of a study?

1. What is the definition of psychology?

The scientific study of individual human behavior and cognitive processes

2. Why do psychologists study behavior and cognition?

1. Identify behaviors that are beneficial (like play) and encourage more of

them

2. Identify harmful behaviors (like health problems) and try to prevent them

3. What is a human/social science?

scientific and systematic study of individual and group behavior, mental processes, and how humans interact with their social and cultural environments

4. What is a scientific approach? (a.k.a., the scientific method)

The approaches focus on specific factors that might explain human behavior

1. The biological approach: focusing on biological factors, such as the brain / Chemical messengers (i.e. hormones and neurotransmitters), Genetics

Nature > Nurture

2. The cognitive approach: focusing on internal (mental) factors, such as thinking patterns, Cognitive deficits (e.g. poor attention). Both nature & nurture

3. The sociocultural approach: focusing on environmental (social and cultural) factors, such as: Parental influences, Childhood experiences (positive and negative), media. Nurture>Nature

5. Why is a scientific approach important when studying psychology?

human behavior and mental processes are complex, subjective, and easily misinterpreted by common sense or intuition

6. What is an independent variable? A dependent variable?

Independent Variable: the factor in a study that researchers manipulate (change / alter / vary) to see the effect it might have on behavior

Dependent Variable: the factor in a study that researchers measure in the study as a potential effect of the manipulation of the IV

7. What is the difference between an independent variable and a dependent variable?

8. Would you consider psychology more of a natural science, or a human/social science. Why?

Why Psychology Is a Social Science

Most institutions and organizations, like the National Science Foundation, group psychology with the social sciences because its main focus is human behavior and society. [1, 2]

• Social Context: Psychologists study how people act in groups, how families shape growth, and how cultural norms affect daily choices.

• Real-World Settings: Topics like relationships, workplace teamwork, and mental health counseling look at humans interacting in real social settings.

• Shared Goals: It works closely alongside fields like sociology and anthropology to explain how people connect and cope. [1, 2, 3]

Why Psychology Is a Natural Science

At the same time, many parts of the field rely directly on the physical and biological world. [1]

• Brain and Biology: Neuropsychology and cognitive psychology study physical brain structures, hormones, and genetic codes.

• Physical Processes: Thoughts and emotions are driven by real electrochemical reactions and biological systems inside the body.

• Scientific Testing: Like chemistry or physics, it uses strict experiments, measurable data, and falsifiable theories to test how the physical brain works

10. How does understanding relationships between variables assist in applying conclusions in psychology?

Understanding relationships between variables is the foundation of psychological research. It allows psychologists to take data gathered in a study and successfully apply it to real-world settings, clinical treatments, and behavioral interventions.

Without understanding these relationships, researchers cannot determine if a finding is a fluke, a direct cause, or simply a coincidence, rendering the conclusions useless for practical application.

11. What are some limitations in conducting experiments in controlled environments?

A significant limitation of conducting research in a highly controlled laboratory environment is its inherently low ecological validity, which restricts the generalizability of the findings. Because a laboratory setting is artificial, it eliminates complex environmental and emotional variables that naturally occur in real-world scenarios.

12. What is a control?

An experimental element kept constant or unaffected to isolate the factor being tested.

• Purpose: Blocks confounding variables (outside noise) that could skew results.

• Control Group: The baseline group of participants who do not receive the active treatment or experimental condition.

12. What is a causal relationship?

If the IV is the only factor that affects the DV, then we can conclude that the IV CAUSES the change in the DV

13. How can true (lab) experiments demonstrate causal relationships?

(A strong answer will use the terms IV, DV, EV, control,

cause)

1. Participants are randomly allocated to the different experimental conditions or groups

2. EVs are controlled for, IV is isolated as the only factor affecting the DV

3. In a controlled experiment

If the IV is the only factor that affects the DV, then we can conclude that the IV CAUSES the change in the DV

14. What are some behaviors that might be difficult to study in a laboratory?

• Social Interactions: Distorted by demand characteristics and the Hawthorne effect because participants know they are being observed.

• Long-Term Shifts: Cultural and developmental changes require years of tracking, which cannot be captured in short lab sessions.

• Trauma & Emotion: Ethical guidelines (protection from harm) prevent researchers from inducing genuine panic, grief, or severe stress.

• Sexual Behavior: Extreme social inhibition and anxiety in a lab environment lead to highly artificial data.

15. What is a correlation? What are positive and negative correlations?

A correlation indicates that as one variable changes, so does the other. However, no causation is implied

Positive correlation: the change for both variables happens in the same direction (both increase or both decrease) e.g.) children’s age and weight

Negative correlation: the change for both variables happens in opposite directions (as one increases, the other decreases) e.g.) A student’s absences from school and grades attained

16. What is the difference between causation and correlation in psychology?

Not all correlation are causation

All causation are correlation

17. What is one alternative explanation for a correlation found in a study?

Confounding variables are simply extraneous variables that actually affect the results

Example: when predicting a child’s reading ability from their shoe size, the confounding variable is AGE

18. What are the aims of psychological theories?

• A theory is an attempt to explain WHY something exists or occurs

• Psychological theories attempt to explain how and why people behave and think in particular ways

• Example: Social Learning Theory attempts to explain all behavior (but most commonly used to explain aggression)

18. What are the aims of models?

• A model is a demonstration or illustration of HOW something works

• Psychological models demonstrate how processes relevant to behavior or cognition occur

• Example: The multi-store model of memory explores how memory is stored according to its nature

Psychological effects

• Psychological effect is a commonly observed, predictable pattern of behavior which is well-supported by research

• Examples:

  • The Mozart Effect (spatial reasoning)

  • The Hawthorne Effect (modify own behavior due to being observed, rather than due to environmental manipulation)

  • The Anchor Effect (remember?)

  • The Stroop Effect (conscious vs unconscious mental effort)

19. What do psychological theories and studies have in common?

both aim to describe, explain, and predict human behavior and mental processes using systematic, evidence-based methods

Mental process(Cognition)

• Internal thought processes

• Can be deliberate and conscious, like memory

• Can also be instinctive and unconscious, like perception

Behavior

Observable actions

Three reasons why psychologists study

behavior and mental processes

1. Cognition (i.e., thinking) is central to the human

experience (can you think of any action that does not

require thinking?)

2. Behaviors and cognition (thoughts) are inextricably

linked. We think before we act (most of the time)

3. How and what we think is equally important as how

we act and behave

Empirical evidence

• Gathered using observation and experimentation

• Objective

• Gathered using a scientific approach

Anecdotal evidence

• Gathered from personal experience or hearsay

• Subjective

• Gathered in an informal and haphazard manner

Treatment group

Receives some kind of treatment that is hypothesized to have an effect (manipulation of the IV)

Control group

Receives no treatment, or one that is designed not to have any effect (e.g. a placebo)

Causation

A cause-and-effect relationship where a change in one variable (the independent variable) directly causes a change in another variable (the dependent variable).

Correlation

- A correlation indicates that as one variable changes, so does the other

- However, no causation is implied

Extraneous variable

• An extraneous variable (EV) is a factor that might affect the results (other than the IV, evidently)

• Examples:

  • Differences in participants (e.g. age, gender, nationality, skills, education) (also known as participant variability)

  • Participants getting better (or worse) after each condition of an experiment (also known as order effects)

  • Participants finding out about the purpose of the study

Negative correlation

A negative correlation means the variables move in opposite directions. When one variable goes up, the other goes down

Positive correlation

A positive correlation means both variables move in the same direction. When one variable goes up, the other goes up too. When one goes down, the other goes down

Phenomenon

an observable, reliably established human behavior, mental process, or effect that has been demonstrated through systematic empirical research

Bidirectional ambiguity

when the direction of a relationship between variables is not clear

True experiment

1. Often take place in controlled environments

so researchers can control for any EVs

2. The researchers create the different

conditions (groups) in the experiment

3. Manipulation of IV affects measurement of

DV. In other words, the IV causes the change

in the DV

Bias

What are the inherent biases of a

researcher? How do we control for this?

Any limitation in objective thinking. Perceiving info through a cognitive filter

Causality

To what extent can we argue that a specific

variable may lead to a certain behavior?

We aim to establish cause-effect relationships between variables

humans are very complex, so causality is not easy to find

Change

How has our understanding of behavior changed over time?

To what extent do we have control over our behavior?

Is our behavior predetermined?

Unexpected biological modification in the body or planned modification through adaptation to evolving circumstances

Can also be understood as DEVELOPMENT

Measurement

How did the researchers measure the variables being studied?

What are the potential problems with the way the variable was

measured?

How might the research method affect the validity of the evidence?

• Human behavior is tough to observe and objectively measure

• Operationalization of variables allows for a reliable measurement and a valid representation of behaviors studied

• Several different instruments to measure variables affecting behavior

• Can also be understood as EVIDENCE

Perspective

• Different approaches to provide a multi-layered understanding of complex humans

• No single perspective explains behavior sufficiently on its own

• Each is based on assumptions about behavior and beliefs about research

Responsibility

• Relationship between researcher and participant is based on respect and with social responsibility in mind

• With animals, justify their use and minimize harm

• Ethical standards in research are central to maximize benefits and costs are minimized

• Ethical considerations evolve

Experimental designs and controls

1. Independent samples

2. Repeated measures

3. Matched pairs

Independent samples:

participants are

randomly allocated into different groups

and they experience only one condition of

the experiment

Pros and cons of independent samples

Pros

Participant expectancy effect: when participants

suspect the results or aims and alter their behavior

- Order effects: when doing more than one task, the

order in

which they are presented may affect the result

(i.e., verb “hit” and

afterward ”smash” in Loftus &

Palmer)

cons

- Participant variability: differences in

participants that could influence results

(e.g. in a jumping test, having all

basketballers in the treatment group)

Repeated measures:

all participants

experience all conditions of the

experiment

Pros and cons of repeated measures

Pros

Limits participant variability and

does not require as many

participants to run the experiment

Cons

Potential order effects. Can be

controlled through counterbalancing

(randomizing the order in which the

treatment/placebo conditions are

presented)

- Higher chance for participant

expectancy effect

matched pairs

participants are matched on some

relevant criteria and then allocated to different

conditions

Pros and cons of matched pairs

Pros:

- Allows to control potential hidden biases

/ EVs (natural tendencies/age/gender) that

may skew results

- Limits participant variability

Cons:

- Harder to run/design: requires

more planning/participants

- May affect the value of

randomization, as selection bias

may happen

Internal validity

the extent to which the

evidence found actually supports a

cause-effect claim. That is, the extent to

which the change in the DV is due to the

manipulation of the IV

Extraneous variables example (4

Order effect

Research bias

Participant variability

Participant expectancy

Controls example (4)

Random allocation

Single-blind design

Double-blind design

Counterbalancing

Field experiment

Manipulation of an IV and measurement of the effect

of a DV in a naturalistic setting

The IV is often a social factor (e.g.

someone’s actions or characteristics)

- Researchers manipulate the IV and

see the effects on behavior by

comparing results across groups

- Social interactions happen in the

“real world” (not in highly controlled

scenarios) so we want to see how

Ecological validity

how well can findings of

research be generalized to real-world,

everyday settings

Quasi-Experiments

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:

1. Random allocation is not possible (irrelevant in repeated

measures)

2. Not all EVs can be controlled

3. IV cannot be generally manipulated

- Quasi-experiments are useful when true experiment

conditions cannot be met due to ethical or practical reasons

What is benefit of using quasi experiment in biological approach?

• Ethical feasibility: Psychologists can safely investigate naturally occurring biological conditions (e.g., comparing individuals with hippocampal damage to healthy controls) without causing harm or altering a participant's biology.

• High ecological validity: It allows the study of real-world biological phenomena in natural settings rather than artificial laboratory environments.

• Tech integration: It provides a practical way to group participants before using neuroimaging tools (like MRI or fMRI) to map specific behaviors to distinct biological profiles.

Natural experiments

An experiment where the IV is

naturally occurring (the

researcher cannot manipulate it)

- Natural experiments are a type

of quasi-experiment (why?)

The IV is usually a naturally

occurring environmental factor

such as gender, age, common

practices, physical characteristics

external validity

The extent to which the findings of a study could be

applied to other people, settings, situations, and

timeframes

population validity

the extent to which

findings could be generalized to other groups

of people (with different characteristics)

Temporal Validity:

the extent to which findings

could apply to different time eras

Case study

An in-depth investigation of a person or a

small group

- Usually conducted over a long period of

time

- Uses a range of different methods

(quantitative and qualitative) to gather a lot

of data (psychological tests, interviews,

experiments, observations, questionnaires,

brain scans, etc.)

Case studies are valuable to explore highly

unique situations that would otherwise be

nearly impossible to study

- Due to ethical concerns, case studies are

hard to replicate (e.g. we cannot harm a

person’s brain to see the outcome / a rat

cannot tell us what is going on when it is

stimulated)