PBSI 302 - Exam 1 TAMU

empirical evidence

evidence that comes from direct experience, scientifically gathered data, or experimentation

tenacity

a method of acquiring knowledge based on superstition or habit (e.g., "Old dogs can't learn new tricks"—but elderly can and do learn)

realism

The philosophy that objects perceived have an existence outside the mind

rationality

The view that reasoning and logic, and NOT authority, intuition, "gut feelings", or faith, are the basis for solving problems.

regularity

A belief that phenomena exist in recurring patterns that conform with universal laws. The world follows the same laws at all times and in all places.

casualty or determinism

The doctrine that all events happen because of preceding causes.

discoverability

The belief that it is possible to learn solutions to questions posed, and that the only limitations are time and resources.

Processes (objectives) of science

1. Description

2. Explanation (development of theories)

3. Prediction (formulated from theories)

Operational definition of control

Defining variables or constructs in such a way that they are measurable; this also serves to eliminate confusion in communication.

research validity

A conclusion based on a research study is valid when it corresponds to the actual or true state of the world.

four facets of research validity

internal validity, external validity, statistical conclusion validity, and construct validity.

internal validity

a type of reliability that examines whether items on a test measure only one dimension, construct, or area of interest

extraneous variable

any variable other than the IV that influences the DV.

example of extraneous variable

background noise

temperature

confounding variable

when an extraneous variable systematically varies with variations or levels of the IV.

example of confounding variable

red bull condition - no distractions for memory test

water condition - people next door playing music during test

we find that red bull ppts have better memory. we could not conclude that red bull improves memory as we have 2 IV's (noise & redbull)

threats (history)

(events outside the lab)—the observed effects between the independent and dependent variable might be due to an event which takes place between the pretest and posttest when this event is not the treatment of research interest (e.g., effects of success/failure [IV] on feelings of depression [DV] with success condition run on a sunny day and failure on a gloomy, dark, cold, rainy day [weather = extraneous variable]).

threats (maturation)

a source of error in a study related to the amount of time between measurements; concerned with naturally occurring changes in research participants (e.g., developmental or gerontological psychology research).

threats (testing)

effects due to the number of times particular responses are measured—familiarity with the measuring instrument (e.g., increased scores on 2nd test).

threats (attrition or mortality)

the dropping out of some participants before a study is completed, causing a threat to validity (e.g., effect of learning strategies [IV] on end of semester grades [DV]; effect of attrition as a result of bad grades would be an extraneous variable).

threats (selection)

many studies compare two or more groups on some dependent variable after the introduction of an IV. Other studies like surveys just assess attitudes or opinions on an issue. In either case, sampling or selection into the study is critical. Samples must be comparable—in multi-group designs—or must represent the population (e.g., survey of attitudes towards endangered species—one would probably obtain very different results as a function of sampling from individuals in the logging industry vs. members of the Society for the Protection of Baby Seals).

threats (regression effects)

tendency of participants with extreme scores on first measure to score closer to the mean on a second testing; a statistical threat (e.g., scores on the 2nd test regress—move either higher or lower—to the true score). • These threats are corrected for by randomization

external validity

is the inference that presumed causal relationships can be generalized to and across alternate measures of cause and effect, and across different types, persons, settings, and times.

threats (population validity)

problems with generalizability to other people

threats (ecological validity)

environment the study is carried out in (laboratory or natural), how the DV was measured and whether the participants know they are being assessed

threats (temporal validity)

Other times (interaction of history and treatment)

Statistical Conclusion Validity

appropriateness of inferences (or conclusions) made from data as a result (or function) of conclusions drawn from statistical analysis. That is, are the IV and DVstatistically related?

threats to statistical conclusion validity

low statistical power, violated assumptions of statistical tests, reliability of measures' scores

construct validity

has to do with labels that can be placed on what is being observed and the extent to which said labels are theoretically relevant. • Construct validity is a question of whether the research results support the theory underlying the research. That is, is there another theory that could adequately explain the same results? - e.g., in polygraph research, is "ANXIETY" a better label than "LYING" for what is being studied?

threats to construct validity

loose connection between the theory and method, "good-subject response", hawthorne effect

these threats to construct validity can be minimized by using

(a) Double-blind procedures (b) Single-blind procedures (c) Deception

TRUE or FALSE: four facets or dimensions of research validity are interrelated and NOT independent of one another.

true

independent variable

variable is the condition manipulated or selected by the researcher to determine its effect on behavior

dependent variable

variable is a measure of the behavior of the participant that reflects the effects of the independent variable.

continuous variable

variable is one that falls along a continuum and is not limited to a certain number of values (e.g., distance or time).

discrete variable

variable is one that falls into separate categories with no intermediate values possible (e.g., male/female, alive/dead, French/Dutch, flying/walking).

pearson's correlation

assumes that both variables are continuous.

point-biserial

most appropriate when one variable is measured in the form of a true dichotomy, and we cannot assume a normal distribution

biserial

most appropriate when one variable is measured in the form of an artificial dichotomy, and we can assume a normal distribution.

phi coefficient

is used when both variables are measured as dichotomies.

quantitative variable

variable is one that varies in amount (e.g., reaction time or speed of response)

qualitative variable

variable is one that varies in kind (e.g., college major or sex). - Qualitative variables are by definition also categorical.

extraneous variable

any variable other than the IV that influences the DV.

confounding variable

when an extraneous variable systematically varies with variations or levels of the IV

measurement

the assignment of numbers to events or objects according to rules that permit important properties of the events or objects to be represented by properties of the number system

labels

When numbers are used as a way of keeping track of things without any suggestion that the numbers can be subjected to mathematical analyses. - Examples include participant ID, university identity number (UIN), and social security numbers.

nominal

Grouping objects or people without any specified quantitative relationships among the categories. - Examples include coding all men as 1; and women as 2. Or cats as 1 and dogs as 2.

ordinal

People or objects are ordered from "most" to "least" with respect to an attribute. There is no indication of "how much" in an absolute sense, any of the objects possess the attribute. There is no indication of how far apart the objects are with respect to the attribute. Rank ordering is basic to all higher forms of measurement and conveys only meager information. - Examples include college football polls, top 5 contestants in a beauty pageant. or metals at the olympics

interval

Most common level of measurement in psychology. Measures how much of a variable or attribute is present. Rank order of persons or objects is known with respect to an attribute. How far apart the persons or objects are from one another with respect to the attribute is known (i.e., intervals between persons or objects is known). Provides information about the magnitude of the attribute for any object or person. - Examples include how well you like this course, where 1 = do not like at all, and 5 = like very much.

ratio

Has properties of preceding 4 levels of measurement in addition to a true zero-point. Rank order of persons or objects is known in respect to an attribute. How far apart the persons or objects are from one another with respect to the attribute is known (i.e., intervals between persons or objects is known). The distance from a true zero-point (or rational zero) is known for at least one of the objects or persons. - Examples include speed (no motion).

reliability

presence of/susceptibility to measurement error. To the extent that the construct is stable, then would expect consistency over time, place, occasion, etc.

validity

extent to which a method measures what it is supposed to measure.

correlation

Correlation coefficients measure the degree of relationship or association between two variables. - Correlation coefficients can assume values of -1.00 to +1.00. The closer this value is to either of these limits, the stronger the relationship between the two variables. And the sign denotes whether the relationship is negative or positive.

test-retest reliability

(temporal consistency or stability)—Involves the repeated administration of the same test to the same sample.

alternate forms reliability

y (temporal consistency or stability, and inter-form consistency or equivalence)—A measure of the extent to which 2 separate forms of the same test are equivalent.

Split-half, odd-even (or random split) reliability (internal consistency)

The primary issue here is one of obtaining comparable halves.

Coefficient alpha (Cronbach's alpha) (inter-item consistency)

This is a measure of interitem consistency (i.e., the consistency of responses to all items on the test). - This is an indication of the extent to which each item on the test measures the same thing as every other item on the test. - The more homogeneous the domain (test), the higher the inter-item consistency.

Scorer reliability or inter-rater reliability and agreement

the extent to which 2 or more raters are consistent, or agree. - reliability = rank order - agreement = magnitude (and rank order)

Criterion-related validity

effectiveness of a test in predicting an individual's behavior in specific situations. • That is, the test or measure is intended as an indicator or predictor of some other behavior (that typically will not be observed until some future date). • With criterion-related procedures, performance on the test, predictor, or measure is correlated with a criterion (i.e., a direct and independent measure of that which the test is designed to predict).

concurrent criterion validity

how well a test outcome is consistent with a criterion that exists in the present

predictive criterion validity

how consistent a test outcome is with a criterion that occurs in the future

postdictive criterion validity

When participant scores reasonably repeat previous outcomes. Example new IQ test scores match previous IQ scores

content-related validity

Content-related validity involves the degree to which a predictor covers a representative sample of the behavior being assessed (e.g., classroom tests). • Content-related validity involves a systematic examination of test content to determine whether it covers a representative sample of the behavior domain being measured. • Content-related validity is typically rational and nonempirical, in contrast to criterion-related validity which is empirical. • The content domain to be tested should be fully described in advance in very specific terms

construct-related validity

The construct-related validity of a test or measure is the extent to which the test may be said to measure a theoretical construct or trait. • A construct is a label for a theoretical dimension on which people are thought to differ. • A construct represents a hypothesis (usually only half-formed) that a variety of behaviors will correlate with one another in studies of individual differences or will be similarly affected by experimental treatments