Research Design and Statistics Flashcards
Analogue Studies
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
Dependent Variable
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
Longitudinal Studies
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
Quasi-Experimental Research
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.
Alpha (Level Of Significance)
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)
Demand Characteristics
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
Interval Scale
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
Program Evaluation
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
Correlation Coefficient
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)
Hawthorne Effect
Refers to a change in performance resulting from participation in a research study ( the novelty of the situation, increased attention, etc.)
Nominal Scale
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
Scales of Measurement
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
Cohort (Intergenerational) Effects
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
External Validity
The degree to which a study’s results can be generalized to other people, settings, conditions, etc.
Multiple Baseline Design
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