Key Research Terms

bias: any influence that may distort the results of a research study and lead to error; the loss of balance and accuracy in the use of research methods.

case study: presentation of data about selected settings, persons, groups or events. Data can have been gathered using variety of different research methods (e.g., questionnaire, observation, historical or literary analysis). Is chiefly descriptive and analytical, usually based on qualitative data, though statistics such as survey findings may be included.

causal relationship: relationship between variables where movements in one or more variable(s) are held to cause changes in the other (s).

coded data: data are put into groups or categories, such as age groups, and each category is given a code number. Data are usually coded for convenience, speed, and handling to enable statistical analysis. construct: a mental state that can’t be directly observed or manipulated, such as love, intelligence, hunger, feeling warm, and aggression; a concept developed (constructed) for describing relations among or between phenomena or for other research purposes.

construct validity: the degree to which the study actually measures and manipulates the elements that the researcher claims to be measuring and manipulating. If the operational definitions of the constructs are poor, the study will not have good construct validity. For example, a test claiming to measure “aggressiveness” would not have construct validity if it really measured assertiveness.

internal validity: the degree to which the study demonstrates that a particular factor caused a change in behavior. If a study lacks internal validity, the researcher may falsely believe that a factor causes an effect when it really doesn’t. Most studies involving humans do not have internal validity because they can’t rule out the possibility that some other factor may have been responsible for the effect.

controls: processes used to make uniform or constant the conditions for carrying out an investigation.

control group: in experimental research, the group or item which does not receive the treatment or intervention under investigation and is used to compare outcomes with the one that does. correlation: the extent to which two or more factors vary in relationship to one another; the extent of association between two or more variables. Correlation does not equal causation. For example, might suggest relationship between academic success and self-esteem, but cannot prove that a change in first variable causes a change in second variable. correlation coefficient: a measure of the degree of relationship between two variables. It usually lies between +1 (showing a perfect positive relationship), 0 (showing no relationship), to -1.0 (showing a perfect negative relationship). dependent variable: variable thought to be determined or influenced by others.

experiment: a special type of study (not all studies are experiments!) that allows researchers to determine the cause of an effect; usually involves randomly assigning participants to groups.

external validity: the degree to which the results of the study can be generalized to other places, people, or times.

hypothesis: a proposition which research sets out to prove or disprove: “experimental” where the hypothesis is a positive statement, or “null” where statement contains a negative.

independent variable: a variable that researcher believes precedes, influences or predicts the dependent variable.

informed consent: giving potential participants information about the study, especially in terms of factors that might lead them to refuse to be in the study, before they decide whether to participate. Institutional Review Board (IRB): a committee of at least five members--one of whom must be a nonscientist--that review proposed research and monitor approved research in an effort to protect human research participants.

literature review: often the first step in the research process, it is a review of the literature on and around the subject of inquiry. Its main purposes are to avoid duplication, to identify gaps in research and to place the researcher’s approach within the work and approaches of others.

primary/secondary sources: primary sources are original firsthand records or materials relating to an event or happening. They may include, for example, official minutes of meetings, diaries, verbatim transcripts of interviews, completed questionnaires or records of the results of experiments. Secondary sources are accounts bases upon these, which usually offer an interpretation, commentary, analysis, or restatement of the primary sources. They can include, for example, books, journal articles, and conference papers.

qualitative data: information gathered in narrative, non-numerical form (e.g., transcript of an interview). Qualitative research used for exploratory (hypothesis-generating) purposes or explaining puzzling quantitative results, while quantitative methods are used to test hypotheses.

quantitative data: information gathered in numerical form. reliability: extent to which the same result will be repeated/achieved by using the same measure.

statistical significance: tests used to estimate the likelihood that the finding in a sample is true of the population from which the sample is derived and not due to chance.

simple experiment: used to establish cause and effect, so this type often used to determine effect of treatment. Participants randomly assigned to either control group with no treatment, while the experimental group receives treatment.

validity: extent to which research findings can be said to be accurate and reliable; degree to which conclusions are justified. Internal validity is extent to which researchers can show that they have evidence for the statements they make; external validity refers to a study’s generalizability.