Research Design and Statistics

Question 1

Analogue Studies

Answer 1

Studies conducted in a ‘facsimile of reality’ (e.g., studies conducted in a laboratory or other artificial setting). A problem with analogue studies is that their results may have limited generalizability

Question 2

Dependent Variable

Answer 2

The variable that is observed and measured in a research study and is believed to be affected in some way by the independent variable. In direct practice evaluation, the client’s functioning is considered the dependent variable

Question 3

Longitudinal Studies

Answer 3

Studies in which a group of subjects are followed and evaluated over an extended period of time in order to assess the effects of aging, natural developmental processes, or one or more other independent variable on one or more dependent variables over time

Question 4

Quasi-Experimental Research

Answer 4

Experimental research in which an investigator’s experimental control is limited; especially his/her ability to assign subjects to groups because intact groups must be used, the variable of interest is an organismic variable, or the study includes only one group that will be compared to itself. A limitation of quasi-experimental research is that it does not allow an investigator to conclude that an observed relationship between variables is a causal one.

Question 5

Alpha (Level Of Significance)

Answer 5

The probability of rejecting the null hypothesis when it is true (i.e., the probability of making a Type I error). The value of alpha is set by an experimenter prior to collecting or analyzing the date. In psychological research, alpha is commonly set at either .01 or .05. (The null hypothesis states there is no relationship between independent and dependent variables and implies that any observed relationship is simply the result of sampling error)

Question 6

Demand Characteristics

Answer 6

Cues in an experimental situation that inform research participants of how they are expected to behave during the course of the study. Demand characteristics threaten a study’s internal and external validity

Question 7

Interval Scale

Answer 7

The scale of measurement that has equal intervals between successive points on the measurement scale. Most standardized educational and psychological tests provide scores that represent an interval scale. With an interval scale, the property of equal intervals allows you to perform the mathematical operations of addition and subtraction with the data

Question 8

Program Evaluation

Answer 8

In social work, assessments carried out to obtain information that can be used to improve social programs and social service accountability. Involves using applied social research to discover the extent to which social programs are carried out efficiently and effectively

Question 9

Correlation Coefficient

Answer 9

A numerical index of the relationship (degree of association) between two or more variables. The magnitude of the coefficient indicates the strength of the relationship; its sign indicates the direction (positive or negative)

Question 10

Hawthorne Effect

Answer 10

Refers to a change in performance resulting from participation in a research study ( the novelty of the situation, increased attention, etc.)

Question 11

Nominal Scale

Answer 11

A scale of measurement in which the variable is divided into unordered groups or categories. When a variable is measured on a nominal scale (or is treated as though it were measured on a nominal scale), the data to be described or analyzed are frequency ata (i.e., the frequency of observations in each group or category). The primary limitation of this measurement scale is that the only mathematical operation that can be performed on nominal data is to count the number (frequency) of cases in each category

Question 12

Scales of Measurement

Answer 12

The first consideration when choosing a statistical technique is usually the scale of measurement of the data that is to be described or analyzed. There are four different measurement scales - nominal, ordinal, interval, and ratio - and each involves dividing a set of observations into mutually exclusive and exhaustive categories. The differences between the four scales are that each provides a different kind of information and allows different mathematical operations to be performed

Question 13

Cohort (Intergenerational) Effects

Answer 13

The effects of being part of a group (cohort) that was born at a particular time and, as a result, was exposed to unique educational, cultural, and other experiences. Cohort effects can confound the results of a cross-sectional study since any observed differences between age groups might be due to these effects rather than to differences in age only

Question 14

External Validity

Answer 14

The degree to which a study’s results can be generalized to other people, settings, conditions, etc.

Question 15

Multiple Baseline Design

Answer 15

A single-subject design that involves sequentially applying a treatment to different ‘baselines’ (e.g., to different behaviors, settings, or subjects). Useful when a reversal design would be impractical or unethical

Question 16

Reversal (Withdrawal) Design

Answer 16

A type of single-subject design that includes, at a minimum, two baseline phases and one treatment phase (e.g., an ABA or ABAB design). The treatment is withdrawn (‘reversed’) during the second and subsequent baseline phases

Question 17

Case Studies

Answer 17

A general term used to describe an in-depth investigation of a single individual, family, organization, etc. A shortcoming is that their results might not be generalizable to other cases

Question 18

Ex-Post Facto Research

Answer 18

After the fact research in which the experimental treatment (independent variable) has been applied prior to the onset of the study. Because ex-post facto studies do not allow the experimenter to control the assignment of subjects to treatment groups, they are considered a type of quasi-experimental research

Question 19

Mode

Answer 19

The measure of central tendency that represents the most frequently occurring category or score in a distribution

Question 20

Reactivity

Answer 20

The response of research subjects that is caused by their awareness of being participants in a research study and/or the knowledge that their behaviors are being observed. Can threaten a study’s internal and external validity. Reactivity may also refer more generally to the tendency for people behave differently because they know they are being observed; this tendency can compromise the validity of a formal or informal observational procedure

Question 21

Arithmetic Mean

Answer 21

The measure of central tendency that is the arithmetic average of a set of scores. Can be used when scores are measured on an interval or ratio scale

Question 22

Descriptive Research

Answer 22

Research conducted to describe behavior rather than to test hypotheses about behavior. Includes observational techniques, surveys and questionnaires, archival research, and case studies

Question 23

Median

Answer 23

The measure of central tendency that is the middle score in a distribution of scores when scores have been ordered from lowest to highest

Question 24

Ratio Scale

Answer 24

The scale of measurement that has equal intervals between successive points on the measurement scale and an absolute zero point. An absolute zero point makes it possible to multiply and divide ratio scores and to determine more precisely how much more or less of a characteristic one subject has compared to another

Question 25

Cross-Sequential Design

Answer 25

Used to assess the effects of aging and/or developmental changes over time. Combines cross-sectional and longitudinal methodologies by assessing members of two or more age groups at two or more different times

Question 26

Internal Validity

Answer 26

The degree to which a research study allows an investigator to conclude that observed variability in a dependent variable is due to the independent variable rather than to other factors

Question 27

Positively Skewed Distribution

Answer 27

A distribution in which scores are ‘piled up’ in the negative (low score) side of the distribution, but a few scores are located in the distribution’s positive tail

Question 28

True Experimental Research

Answer 28

Experimental research that provides the investigator with maximal experimental control. Most important, when conducting a true experimental research study, an investigator can randomly assign subjects to groups, which makes it easier to determine if observed variability in the dependent variable was actually caused by the different levels of the independent variable

Question 29

Cross-Sectional Studies

Answer 29

Studies conducted to assess the effects of aging and/or developmental changes over time (e.g., to assess the effects of age on IQ). Involves comparing groups of individuals representing different age groups or developmental levels at the same point in time. Cohort effects are a possible confound when conducting these studies

Question 30

Independent Variable

Answer 30

The variable that is manipulated in a research study for the purpose of determining its effects on the dependent variable. Also known as the experimental variable. In direct practice evaluation, the intervention is the independent variable

Question 31

Ordinal Scale

Answer 31

The scale of measurement in which the variable is divided into ordered categories, scores, or levels. A limitation of ordinal scores is that they do not lend themselves to determining just how much difference there is between scores. For example, we can’t say that person with a rank of 10 has twice as much of the characteristic as the person with a rank of 5, only that he/she is ranked higher

Question 32

Single-Subject Designs

Answer 32

Research designs that involve obtaining repeated measurements from a single subject over a specific period of time to measure changes in behaviors, attitudes, or beliefs. Each single-subject design includes at least one baseline (no treatment) phase and one treatment phase. As a result, the subject acts as his/her own no-treatment ‘control’. In most single-subject designs, the dependent variable (behavior, attitude, or belief) is measured repeatedly at regular intervals throughout the baseline and treatment phases. If status on the dependent variable is stable within each phase of the study and changes only at the same time that the independent variable (treatment) is applied or removed, then it is likely that any observed change in the dependent variable is due to the effects of the independent variable rather than to history, maturation, or another extraneous factor.