Psychology Research Methods Ch3

Variable

It is something that varies.

Values

Levels

Constant

Something that could potentially vary but that has only one level in the study in question.

Measured Variables

These are observed and record its levels. They can be concrete or abstract.

Manipulated Variables

These are controlled by experiments by determining it levels by assigning participants to the different levels of that variable.

Conceptual definitions

A researcher's definition of a variable at an abstract level.

Operational definitions

The process of turning a concept of interest into a measured or manipulated variable.

Claim

The argument someone is trying to make.

Frequency Claim

How often or the percentage of something that happens.

Association Claim

It suggests that the two variables are related, but they do not cause one another.

Causal Claim

The verb or action suggests that one variable brings about another reaction in another.

Frequency Claim

One variable. Always measured.

Anecdotal

They do not report the results of a study. Rather they tell an illustrative study.

Correlate

When one variable changes, the other tends to change as well.

Association Claim

Two variables. Measured.

Positive Association

High and High. Low and low.

Scatterplot

One variable is plotted on the y-axis and the other variable is plotted on the x-axis. Each dot represents one participant in the study.

Negative Association

High low. Low high.

Zero Association

No association between the variables.

Curvilinear Association

The level of one variable changes its pattern as the other variable increases.

Predict

Using association to make our estimates more accurate.

Association

It helps us make predictions by reducing the size of our prediction errors. The stronger it is, the more accurate our predictions are.

Construct Validity

When you ask how well a study measured or manipulated a variable, you are testing this.

Construct Validity

It is concerned how accurately a researcher has operationalized each variable.

Generalizability

How well do those participants represent the population they are supposed to represent?

External Validity

How well the results of the study generalize to, or represent, people and contexts besides those in the study itself.

Statistical Validity

It is the extent to which those statistical conclusions are accurate and reasonable.

Type I Error

Saying there is a relationship when there is not.

Type II Error

Saying there is not a relationship when there is.

Internal Validity

In a relationship between one variable and another, the degree to which we can say that A, rather than some other variable is responsible for the affect on B.

Covariance

One of the three rules for establishing causation, stating that the proposed causal variable must vary systematically with changes in the proposed outcome variable.

Temporal Precedence

The variable comes first in time, before the other variable.

Experiment

One variable is manipulated and the other is measured. Used for causal claims.

Independent Variable

Manipulated variable.

Dependent Variable

Measured variable.

Random Assignment

Each person has a equal to chance to be in either group.

Polls

They are ill suited to establishing temporal precedence.