**RESEARCH TERMS**

** **(Source:
Sommer, B and Sommer, R. A (1997).
__A Practical Guide to Behavioral Research__)

**Alternative
Hypothesis**: Working or research hypothesis, and alternative to the null
hypothesis, stated in positive terms (i.e., that there will be an effect)

**Analysis of
Covariance (ANCOVA):** Takes into account scores on some other variable
believed to affect the action of the independent variable

**Analysis of Variance
(ANOVA):** Statistical technique for comparing differences between means

**Anonymity**:
Researcher does not know the identity of the participants in the study

**Applied Research:**
Systematic procedures to answer pressing questions

**Attitude Scale**:
Type of questionnaire designed to produce scores indicating the overall degree
of favorability of a person’s attitude on a topic

**Average:** Generic
term referring to various measures of central tendency- the mean, median, and
mode

**Bar Graph:** A
graphic representation of results using bars to indicate frequency of response

**Blind Testing**: In
a sensory evaluation or drug research, blind testing indicates the subject is
not aware of the stimulus.

**Browser Program:**
Required for navigating the World Wide Web

**Case Study:**
In-depth investigation of a single instance

**Categorical:**
Refers to variables that have levels that are mutually exclusive

**Causal Patterns:** Relationships
of cause and effect

**Central Tendency:**
Number (statistic) that best summarizes the characteristics of a sample as a
whole

**Chi-Square (X Squared**):
Statistical test used with categorical data to test whether an obtained
distribution of scores differs reliably from what would be expected by chance.

**Coding:**
Transformation or reduction or raw data into a set of standard categories for
statistical analysis

**Comparative Rating
Scales**: Respondent compares individual with others in the same category

**Concurrent Validity:**
Correlation of a test with present behavior, or with other existing tests or
measures; one type of criterion validity

**Confidentiality: **Participant
or respondent identity is known to researcher, but is not publicly revealed.

**Confounding:**
Confusion of the effects of variables, resulting in the inability to determine
which variable is the cause of the observed effect.

**Constants:**
Qualities that do not vary

**Construct Validity:**
Linkage of the test measurement to specific theoretical constructs, the
relationship of a test to theory

**Content Validity:**
Degree to which test items assess the domain that a test claims to cover, the
relevance of the items to the behavior measured

**Contingency Table: **Table
used to record the relationship between two or more variables. The observed
frequencies are placed into the cells of the table.

**Continuous Variable:**
Variable whose levels can take on any value within the lowest and uppermost
limit of the variable, for example time or income

**Control Group**:
Subject group that resembles the experimental group in every respect except
that it is not exposed to the independent variable

**Convenience sampling:**
taking what is available as your sample

**Correlated measures:**
Groups being compared have been matched on some characteristic, or the same
people have been tested before and after an experimental treatment

**Correlation:**
Association between two sets of scores. Often expressed in terms of a
correlation coefficient

**Correlation
Coefficient:** Indicates the degree of relationship between two sets of
scores, a number that can range from +1.0 to -1.0.

**Criterion Validity**:
Relationship of the test scores to other measures of the same characteristics

**Degrees of Freedom**:
(df): Number of values that
are free to vary after certain restrictions have been placed on the data. Used
to evaluate the results of various statistical tests; related to the sample
size and number of levels of the independent variable

**Dependent Variable:**
Consequence or outcome or the manipulation, the variable that is affected by
the independent variable; synonyms are outcome, response, or criterion variable

**Descriptive
statistics:** Techniques to organize and summarize data

**Equivalent forms:**
Two different, but comparable, forms of a scale; used for assessing reliability
or to avoid practice effects

**ERIC:** Educational

**Expected Frequencies
(E): **Represent the null hypothesis- what you would expect by chance

**Experimental Group**:
Subjects exposed to the levels of the independent variable; also called the
treatment group

**Experimental
Variable: **Variable that is manipulated or systematically altered by the
experimenter; synonyms are independent variable or predictor variable

**External Validity:**
Generalizability of research findings

**Extraneous Variables**:
Variables, in addition to the independent variable, that might be affecting the
dependent variable (outcome)

**Face Validity: **Appearance
of being a valid measure of something; a measure that “looks right” to an
outside observer. A form of content validity

**Factor: **Independent
variable or treatment. A study investigating the effects of age and education
on attitude would be a two-factor study.

**Factorial Design:**
ANOVA design involving more than one independent variable (factor)

**Focus Group:**
Group interview designed to explore what a specific set of people think and feel about a topic

**Format:**
Structure; pertains to the appearance, order, and wording of items in a
questionnaire or interview; in contrast to content, which refers to meaning

**Frequency**: Number
of times a score or category level occurs

**Frequency
Distribution**: Arrangement of scores from highest to lowest, together with
the frequency of each score

**Histogram:**
Particular type of bar graph

**Hypothesis:**
testable statement logically derived from theory or observation; can be either
confirmed (accepted) or disconfirmed (rejected)

**Independent Variable**:
Variable that is manipulated in order to measure its effect on some outcome;
synonyms are experimental variable, or predictor variable

**Inferential
statistics:** Statistical techniques used to make generalizations from
samples to populations

**Informed Consent:**
Those who participate in research studies should understand what is involved
and freely consent to participate

**Institutional Review
Board (IRB**): Group of people with formal responsibility for reviewing
submitted research proposals in terms of ethics and protection of the
participants

**Interaction**:
Using ANOVA, the outcome produced by changes in one variable differs depending
upon the levels of a second variable

**Internal Validity:**
Degree to which a procedure measures what it is supposed to measure

**Interval Scale:**
Level of measurement that provides information about size or direction, plus
having equal intervals between scale points

**Item Analysis:**
Shows the degree that the various items in a scale or test “hang together”

**Likert**** Scale: **Type of attitude scale
containing statements that are clearly favorable or clearly unfavorable, to
which respondent indicates degree of agreement

**Matched Groups:**
Assigning subjects so that the experimental and control groups are as similar
as possible.

**Mean Comparisons**:
Comparisons or contrasts between individual means to locate where the
significant difference lies.

**Median**: Midpoint
of a distribution when all the scores are arranged from highest to lowest.

**Mode:** Single
score that occurs most often in a distribution.

**Nominal Measures:**
Characteristics assigned to categories. No underlying continuous dimension

**Normal Curve**:
Symmetrical bell-shaped curve which often approximates the frequency of
occurrence of events in nature

**Null Hypothesis**:
Assumes that differences produced by the research manipulation are due to
chance fluctuations and that the independent variable has no effect on the
dependent variable. Generally, the researcher hopes to disprove the null hypothesis.

**Ordinal Scale**:
Characteristics can be ordered along an underlying dimension, but no
information is provided about the distance between points; only provides
information about increasing or decreasing size or direction

**Pilot Study**:
Preliminary use of a procedure designed to identify problems and omissions
before the actual study is conducted

**Positive correlation**:
An increase in one variable is accompanied by an increase in the other

**Probability Level**:
When used in statistics, it indicates the likelihood that an obtained
difference on a statistical test is due to chance alone.

**Probability Sample:**
Sample that is drawn in such a way that the probability for the inclusion of
nay given individual can be estimated. Two general types of probability samples
are random samples and stratified samples

**Purposive Sample**:
Type of non-probability sample in which the individuals considered most
relevant to the issue studied are selected for inclusion

**Quasi-experiment**:
Non-random assignment of subjects to conditions; the experimenter lacks direct
control over the independent variable; also called a natural experiment

**Random sample**:
Type of probability sample in which every individual in the entire population
being studied has an equal chance of being selected

**Range: **Measure** **of**
**dispersion or variability, computed by subtracting the lowest from the
highest score

**Ratio Scale:**
Level of measurement that contains information on direction, possesses equal
intervals, and an absolute zero point

**Regression**:
Pertains to the correlation; the relationships between sets of scores

**Reliability: **Consistency
in measurement; the repeatability or replicability of
findings; stability of measurement over time

**Reliability
Coefficient:** Coefficient of correlation between two administrations of a
test or other measures

**Repeated Measures
Design: **Research design involving the same subjects studied at different
times or under different conditions

**Sample: **Subset of
the population

**Sample Bias: **Error
introduced by a sampling procedure that favors certain characteristics over
others

**Sampling Error: **Chance
variation among samples selected from a single population

**Snowball Sample: **Type
of purposive (non-random) sample in which the researcher asks respondents for
other people that should be contacted

**Split-half
Reliability: **Dividing a scale or test into two halves which are then
compared

**Standard Deviation:**
Measure of dispersion or variability; abbreviated as s or SD

**Stratified Sample: **Type
of probability sampling in which the characteristics of the sample are selected
to be proportionate to those present in the total population

**Treatment Condition: **Refers
to the presence of the independent variable, as opposed to the control
condition in which the independent variable is absent

**Treatment Group**: Subjects exposed to the levels of the
independent variable; also called the experimental group

**Variability:**
Amount of spread or dispersion within a distribution of scores