The four goals of behavioral science

Describe, predict, determine, explain

Basic research:

Increases knowledge and understanding, without requiring an immediate practical use

Applied research:

Addresses a real-world problem.

Research question

The broad question the researcher wants to answer.

Hypothesis

A proposed explanation or relationship that can be tested.

Prediction

A specific expected result of a study.

Where do researchers get ideas?

Everyday observations, Previous research, Theories, Practical problems, and Curiosity

Primary source:

Reports original research conducted by the authors, such as an empirical journal article.

Secondary source:

Summarizes, reviews, or discusses research conducted by others.

Empiricism

Use of objective, verifiable observations to answer questions and draw conclusions.

Scientific method

A systematic process for answering questions using observation, measurement, evidence, and testing.

Prediction

A specific expected outcome based on a hypothesis or theory.

Construct

An abstract concept that researchers want to study. like depression or anxiety

Empirical Article

An empirical article reports research based on observations or data collected by researchers.

Operational Definition

A precise explanation of how a variable is measured or manipulated in a particular study.

Correlation

A correlation is a statistical relationship between variables. Correlation does NOT automatically mean causation.

Third-Variable Problem

A third variable may explain the relationship between two variables.

Independent Variable

The variable the researcher manipulates.

Dependent Variable

The variable the researcher measures to determine whether it changes.

Experimental Research

Research in which the researcher manipulates an independent variable to examine its effect on a dependent variable.

Nonexperimental Research

Researchers measure variables but do not manipulate an independent variable.

Sample vs. Population

The larger population vs what was actually studied

Construct validity

Does the measure actually represent the construct?/Did we measure the right thing?

Internal validity

Can we confidently conclude that the independent variable caused the outcome?/Did X really cause Y?

External validity

Can the findings apply to other people, settings, or situations?/Can we generalize the results?

Statistical validity

Are the statistical conclusions appropriate and supported by the data?/Did we interpret the data correctly?

Generalizability

The degree to which research findings can be applied to:

Confounding Variable

A variable that creates an alternative explanation for the results.

Reactivity

Participants change their behavior because they know they are being observed or studied.

Replication

Repeating a study to determine whether the results can be reproduced.

Discriminant validity

Discriminant validity is supported when a measure is not strongly related to measures of different constructs that it shouldn't be related to.

Convergent validity

Convergent validity is supported when a measure is strongly related to other measures that should measure the same or similar construct.

Concurrent validity

Concurrent validity asks whether a measure is related to another measure of the same or closely related construct that is already accepted.

Construct validity

Does the measure actually measure the construct it is supposed to measure?

face Validity

Face validity asks whether a measure appears to measure what it is supposed to measure.

Content Validity

Content validity asks whether a measure adequately covers the different aspects of the construct.

Predictive Validity

Does the measure predict something it should predict in the future?

Concurrent validity

Concurrent validity asks whether a measure is related to another measure of the same or closely related construct that is already accepted.

Nominal Measurement

Categories with no meaningful order.

Ratio Measurement

zero means zero like Hight or age

Interval Measurement

Values have: Meaningful order, Equal intervals between values But zero does not represent a true absence of the variable. Classic example: 0°C doesn't mean "no temperature."

Ordinal Measurement

Categories that have a meaningful order, but the differences between categories aren't necessarily equal./ Freshman → Sophomore → Junior → Senior

Convergent validly

Should be related → is related

Discriminant validay

shouldn't be related → isn't strongly related

Interrater Reliability

This is important when researchers use people to observe or rate behavior.

Internal Consistency

Internal consistency asks whether the different items on a measure are consistently measuring the same construct.

Test-Retest Reliability

Test → wait → test again

Measurement Error

Measurement error is the part of a measurement that reflects random or unwanted influences rather than the true value.

Cronbach’s alpha

An indicator of internal consistency reliability assessed by examining the average correlation of each item (question) in a measure with every other question.

Pearson product-moment correlation coefficient

A type of correlation coefficient used with interval and ratio scale data. In addition to providing information on the strength of relationship between two variables, it indicates the direction (positive or negative) of the relationship.

split-half reliability

A reliability coefficient determined by the correlation between scores on half of the items on a measure with scores on the other half of a measure.

item-total correlation

The correlation between scores on individual items with the total score on all items of a measure.

alternate forms reliability

Assessment of reliability by administering two different forms of the same measure to the same individuals at two points in time.

interrater reliability

An indicator of reliability that examines the agreement of observations made by two or more raters (judges).

internal consistency reliability

Reliability assessed with data collected at one point in time with multiple measures of a psychological construct. A measure is reliable when the multiple measures provide similar results.

true score

An individual’s actual score on a variable being measured, as opposed to the score the individual obtained on the measure itself.