Experimental Psychology Techniques and Statistical Methods

Experimental Method

research techniques used to investigate cause and effect relationships between variables

Independent Variable (IV)

the researcher manipulates -> factor that researchers are testing to see if causes changes in behavior or outcomes

"I.C.E"

Independent is Controlled for an Effect

Dependent Variable (DV)

observed and measured for changes in an experiment -> outcome or response that may be affected by the IV

"D.R.E.A.M"

an acronym related to the dependent variable.

Confounding Variable

wasn't accounted for or controlled in the study but still affects results

Operational Definition

specifies how a research will measure and manipulate variables in a study

Experimental Groups

the participants in the group are exposed to the IV

Control Group

participants who are not exposed to the IV -> providing a baseline for comparison

Random Assignment

method used to assign participants to different groups in an experiment randomly

Placebo Effect

the phenomenon where individuals experience improvement in their condition solely because they believe they are receiving a beneficial treatment

Experimental Biases

researchers expectations or beliefs about the outcome of a study influence the result

Single-Blind Study

participants are unaware

Double-Blind Study

both the participants and the researchers conducting the study are unaware of who belongs to the external or controlled group

Sample

refers to a subset of individuals or cases from a larger population -> used to make inferences about the population as a whole

Representative Sample

subset of the population where it accurately represents the demographic, characteristics, and diversity

Random Sample

participants have an equal opportunity to be included in -> minimize influence of research bias and increase generalizability

Sample Bias

when sample is not representative of the larger population -> inaccurate/misleading results

Generalizability

extent to which research findings obtained from a sample can be applied or generalized to a larger population

Statistics

a large amount of data can be collected in research studies

Descriptive Statistics

refers to numerical measures used to summarize and describe the characteristics of a dataset.

Inferential statistics

Involves using data from a sample to make inferences or predictions about a larger population.

Measures of Central Tendency

Statistical tools used to describe the central or average value of a set of data.

Mean

The average value (adding then dividing).

Median

Middle value of a data set.

Mode

Most frequently occurring value.

Range

Represents the difference between the highest and lowest values in a data set.

Normal Curve or Bell Curve

The majority of the data falls near the center, or mean, of the distribution, with progressively fewer values occurring further away from the mean in both directions.

Regression to the Mean

When extreme scores tend to get closer to the average when measured again.

Positive Skew

Majority of the data clusters on the left side, with the tail extending to the right, suggesting the presence of unusually high values.

Negative Skew

Bulk of the data clusters on the right side, with the tail to the left, indicating exceptionally low values.

Standard deviation

A way to measure how spread out or close together numbers are in a group.

Percentile Rank

Measure that indicates the percentage of scores in a distribution that are equal to or below a value.

Bimodal distribution

Distribution in which there are 2 distinct peaks on a histogram or frequency distribution graph.

Statistical Significance

Likelihood that observed results in a research study are not due to chance.

P-value

A value below a certain threshold (often set at 0.05) indicates that the observed results are unlikely to have occurred by chance alone.

Effect Size

Large effect size indicates a substantial difference; small effect size indicates a minimal difference.

Meta Analysis

Multiple research studies on the same topic to draw conclusions, combining data from various studies to increase overall sample size and statistical power.

Institutional Review Board (IRB)

Committee responsible for reviewing and approving research proposals to ensure that they meet ethical standards.

Protection of Participants from Harm

Emphasizes the obligation of researchers to minimize risk and ensure the well-being of participants.

Informed Consent

Individuals agree to participate in a research study after being provided with info about the purpose, procedures, risks, benefits, and their rights.

Informed Assent

Specifically applies to research involving children or individuals with limited decision-making capacity, involving providing them with understandable info about the study.

Confidentiality

Handle sensitive data/personal information with discretion and confidentiality.

Deception

Involves misleading participants about the true purpose or nature of the study, sometimes necessary to achieve research objectives.

Confederates

Individuals who are part of a research study but are actually working in collaboration with the researcher and are aware of the true purpose.

Debriefing

Providing participants with information about the true nature, purpose, etc., of the study immediately after.