Lab 1 Exam Study Guide

factors manipulated, changed, or varied by the experimenter to see if they cause changes in some other factor

Independent variable

factors being observed or measured by the experimenter to see whether or not they change as a function of the changes in the independent variable.

Dependent variable

any other factors that are not allowed to vary, but instead, are controlled or held constant throughout the course of the experiment.

Control variables

any variables that you're not investigating that can potentially affect the dependent variable of your research study.

Extraneous variables

any extraneous variable that covaries with (or is confounded with) the independent variable.

Confounding variable

a type of extraneous variable that not only affects the dependent variable, but is also related to the independent variable.

Confounding variable

A design that looks for differences between two or more different groups.

Between-subjects design

Comparing the attention span of a group of students in a morning class with the attention span of different students in an afternoon class. In other words, comparing two completely different groups of individuals.

Between-subjects design

A design that looks for differences within the same group that is tested one or more times (sometimes called a repeated-measures design since we are repeatedly measuring the same participants).

Within-subjects design

Observing the attention spans of the same groups of students when they are taking a class both in the morning and then later in the afternoon. Thus, the same group has behavior that is measured multiple times.

Within-subjects design

Observation: People seem happier when they have lollipops. Do lollipops make people happier? What is your independent variable?

Presence or absence of a lollipop

Observation: People seem happier when they have lollipops. Do lollipops make people happier? What is your dependent variable?

Happiness level

Time of day the students take a course

Independent variable

Attention span of students taking the course measured via time attending to the lecture.

Dependent variable

an abstract, unobservable concept or mental framework used to describe and measure human mind and behavior

Construct

The degree to which your measure produces consistent, repeatable results

Reliability

The degree to which your measure actually measures what it’s supposed to measure

Validity

Gives the identical measure twice, and compares score 1 with score 2

test-retest reliability

the degree to which a psychological test produces stable, consistent scores when given to the same group of people on two or more separate occasions

test-retest reliability

Extent to which several different tests intended to measure the same psychological construct give comparable results

Convergent validity

Measure predicts behavior that the theory claims to explain

Construct validityTest appears “on-the-face-of-it” to measure what it says it measures

Test appears “on-the-face-of-it” to measure what it says it measures

Face validity

Administer two different variations of the measure, and compare test A with test B

equivalent-form reliability

Split the measure in half (e.g., odd/even Qs), and compare scores on two halves

Split-half reliability

the average score in a distribution; Used when the distribution is normally distributed (not skewed) and we want to include all of the scores

Mean

the middle score in a distribution; 50% of scores fall above the median and 50% of the scores fall below the median; Used when the distribution has extreme scores – extreme scores are either much higher or much lower than most of the other scores (ex: skewed distributions)

Median

the most common score or the score that occurs most frequently in the distribution; Used with categorical data (ex: majors, brands)

Mode

average amount each individual score falls above or below the mean

Standard Deviation

the range of values that comprises the middle 50% of the data; used with skewed distributions

Interquartile Range

highest score minus the lowest score

Range

a numerical value between -1.0 and +1.0 that measures the strength and direction of the relationship between two variables. In psychology, it is usually represented by the letter r.

correlation coefficient

measures the likelihood that your study's results happened by random chance alone, assuming there is no actual effect or difference (the null hypothesis).

p-values

measure of the magnitude or strength of the result

Effect size

describe what already exists in a group or population

Descriptive studies

Measures and describes the relationship between two variables

Correlational studies

Demonstrates cause-and-effect relationship

Experimental

IV cannot be manipulated by the researcher. Demonstrates cause-and-effect relationship.

Quasi-experimental

IV is manipulated by the researcher. Demonstrates cause-and-effect relationship.

True experiments

a change in one variable directly causes a change in another variable

Casual relationship

ability to GENERALIZE the findings to the real world

External validity

ability to determine if a CAUSAL relationship exists between IV and DV

Internal Validity

Depth information that can be gathered by only one eye.  

Monocular cues

Depth information gathered from the separation between an individual’s two eyes.

Binocular cues

The magnitude of difference between the images projected on an individual’s two eyes. As an object comes closer to us, the differences in images between our eyes becomes greater.

Binocular/Retinal Disparity

As an object comes closer our eyes have to come together to keep focused on the object

Convergence