IB Psych: Types of Experiments

Lab Experiment

IV is changed in a controlled setting

1. High control = high IV

2. Low realism

Field Experiment

IV is changed in a real-word setting

1. More natural behavior

2. Less control = Lower validity

Quasi Experiment

Groups are pre-existing, not randomly assigned.

1. No random allocation.

2. Lower Internal validity

Natural Experiment

IV changes naturally, not by researcher

1. Real-world situation

2. No control over IV

Correlational Study

Measures relationship between 2 variables.

1. No manipulation = no causation.

2. Useful when experiments aren’t possible

Participant Observation (Emic Approach)

Researcher joins the group being studied

1. Deep insight

2. can be biased

Non-Participant Observation (Etic approach)

Researcher watches without joining in

1. More objective

2. Less understanding

Covert Observation

Participants don’t know they’re being observed

1. Natural behavior

2. Ethical issues about consent if not public

Overt Observation

Participants know they are being observed

1. Demand Characteristics/ Biases

2. Ethically transparent

Case Study

In-depth study of one person, group or situation.

1. Uses method triangulation (many data sources)

2. Rich, detailed insight

Unstructured Interview

Flexible, open conversation guided by participant responses.

1. No fixed script = natural flow

2. Needs skilled interviewer

Semi- Structured Interview

Mix of set questions and follow-ups.

1. Balance of structure and freedom

2. Open and closed questions

Structured Interview

Uses a fixed set of pre-written questions in a set order.

1. Standardized = easy to compare responses

2. Less flexible, may miss deeper insight

Focus Group

Group discussion on a shared topic.

1. Builds trust and openness

2. Researcher is a moderator

Dependent Variable

it depends on what the researcher did

Independent Variable

I control it