2022 Introduction to Statistics in Research Mitchell 2nd ed

I N T R O T O R E S E A R C H : D A T A V I S U A L I Z A T I O N & C O M M O N S T A T T E S T S

Histogram: essentially a graphical bar chart with groups of continuous data values in equal intervals with one bar for each interval. A plot that summarizes how data are distributed. Can be unimodal, bimodal, or multimodal (three peaks). It can also be skewed with a tail to the left (negatively skewed) or a tail to the right (positively skewed).

Homoscedasticity: In a scatter plot, you can take a slice through the plot and it is not much different. (see illustration above).

Hypothesis: a proposition formulated for empirical testing; a tentative descriptive statement that describes the relations between two or more variables.

Hypothesis testing: Statistical hypothesis testing is formalized as deciding between rejecting or not rejecting the null hypothesis. Two types of errors can result from any test: Type 1 Error (rejecting the null hypothesis when it is true) and Type 2 Error (failing to reject the null hypothesis when it is false). Independent variable: in regression, the independent variable is the one that is supposed to explain the other. Usually plotted on the horizontal axis. The variable manipulated by the researcher with the intent of effecting change on the dependent variable.

Individual depth interview (IDI): a type of interview (structured, semi-structured, or unstructured) that encourages the participant to talk extensively and asked to share as much information as possible.

Inferential statistics: a term that describes the estimation of population values and the testing of statistical hypotheses.

Informed consent: participants give full consent to participating in a study after receiving full disclosure of the procedures of the proposed survey/study.

Institutional Review Board: a Human Subjects Committee that reviews research proposals.

Internal validity: the ability of a research instrument to measure what it is purposed to measure. Adams & McGuire (2022) define it as “the extent to which you can demonstrate a causal relationship between you r indep endent variable (IV) and your dependent variable (DV)” (p. 54).

Internal consistency: the consistency of participant responses to all the items in the scale. See Cronbach’s alpha.

Inter-quartile Range (IQR): easiest to understand if you look at a box plot. To calculate take the upper quartile minus the lower quartile. Sometimes referred to as the midspread or the distance between the hinges in a boxplot.

Interviewer error: errors that result from interviewer influence on the participant through instruction, voice inflection, body language, order of questions, etc.

k -independent-samples tests: significance tests in which measurements are taken from three or more samples (ANOVA for interval or ratio measures, Kruskal-Wallis for ordinal measures, chi-square for nominal measures).

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