Scope and Methods Final Flashcards
cohort
a group of people who all experience a significant event in roughly the same time frame
randomized experimental designs
posttest design, repeated-measurement design, multiple- group design
non-randomized experiment designs
quasi- experimental design
cross-sectional design
a research design in which measurements of independent and dependent variables are taken at the same time
field experiments
experimental designs applied in a natural setting
intervention analysis
a non-experimental time series design in which measurements of a dependent variable are taken both before and after the introduction of an independent variable
multiple group design
experimental design with more than one control and experimental group
natural experiment
a study in which there is random assignment or as if random assignment of units to experimental and control groups but the researcher does not control the randomization process or the manipulation of the treatment factor
observational study
a non-experimental research design in which the researcher simply observes differences in the dependent variable for naturally acquiring treatment control groups
period effect
an indicator or measure of history effect on a dependent variable during a specified time
posttest design
a research design in whihc the dependent variable is measured after, but not before, manipulation of the independent variable
quasi experimental design
a research design that includes treatment and control gorups to which individuals are no assigned randomly
repeated measurement design
a plan that calls for making more than one measure or observation on a dependent variable at different times over the course of the study
time series design
a research design (sometimes called a longitudinal design) featuring multiple measurements of the dependent variable before and after experimental treatment
trend analysis
a research design that measures a dependent variable a different times and attempts to determine whether the level of the bariable is changing and if it why
branching question
a question that sorts respondents into subgroups and directs these subgroups to different parts of the questionnaire
closed ended question
a question with response alternative provided
content analysis
a systematic procedure by which records are transformed into quantitative data
double barreled question
a question that really two questions in one
filter question
a question used to screen respondents so that subsequent questions will be asked only of certain respondents for whom the questions are appropriate
leading question
a question that encourages the respondent to choose a particular response
open ended question
a question with no response alternative provided for the respondent
question order effect
the effect on responses of question placement within a questionnaire
questionnaire design
the physical layout and packaging of a questionnaire
response rate
the proportion of respondents selected for participation in a survey who actually participate
response set
the pattern of responding to a series of questions in a similar fashion without careful reading of each question
sample population congruence
the degree to which sample subjects represent the population from which they are drawn
single sided question
A question in which the respondent is asked to agree or disagree with a single substantive statement
two sided question
a question with two substantive alternatives provided for the respondent
central tendency
the most frequent, middle, or central value in a frequency distribution
cummulative percentage
the total percentage of observations at or below a value in a frequency distribution
data matrix
an array of rows and columns that stores the values of a set of variables for all the cases in a data set
descriptive statistic
a number that because of its definition and formula, describes certain characteristics or properties of a batch of numbers
dispersion
the distribution of data values around the most frequent, middle, or central value
frequency distribution
the number of observations per value or category of a variable
interquartile range (IQR)
the difference between the third and first quartiles
negatively skewed
a distribution of values in which fewer observations lie to the left of the middle value and those observations are fairly distant from the mean
normal distribution
a distribution defined by a mathematical formula and the graph of which has a symmetrical bell shape
outlier
a value that is far greater or smaller than other values in a recorded variable
positively skewed
a distribution of values in which fewer observations lie to the right of the middle value and those observations are fairly distant from the mean
relative frequencies
percentages or proportions of total numbers of observation in a frequency distribution that have a particular value
resistant measure
a measure of central tendency that is not sensitive to one or a few extreme values in a distribution
standard deviation
a measure of dispersion of data points about the mean for interval and ration level data
variance
a measure of dispersion data points about the mean for interval and ration level data
alternative hypothesis
a statement about the value or values of a population parameter.
confidence interval
the range of values into which a population parameter is likely to fall for a given level of confidence
confidence level
the degree of belief or probability that an estimated range of values includes or covers the population parameter
null hypothesis
a statement that a population parameter equals a single or specific value. Difference between two populations is zero
research hypothesis
a statement about the value or values of a population parameter.
statistical hypotheses
two types of hypotheses essential to hypothesis testing: null hypotheses and research or alternative hypotheses
statistical significane
the probability of making a type 1 error
test of statistcal significance
a convention for testing hypotheses that focuses on the probability of making a type 1 error
type 1 error
error made by rejecting a null hypothesis when it is true
type 2 error
error made by failing to reject the null hypothesis when it is not true
z score
the number of standard deviations by which a score deviates from the mean score
Analysis of variance (ANOVA)
a technique for measuring the relationship between one nominal or ordinal level variable and one interval or ratio level variable
chi square (x^2) statistic
a statistic used to test whether a relationship is statistically significant in a cross tabulation table
control by grouping
a form of statistical control in which observations identical or similar to the control variable are grouped together
correlation coefficient
in regression analysis, a measurement of the strength and direction of the linear correlation between two quantitative variables also called product moment correlation pearsons r or r
cross tabulation or contingency table
also called a cross classification that array displays the joint frequencies and relative frequencies of two categorical (nominal or ordinal) variables
direction of a relationship
an indication of which values of the dependent variable are associated with which values of the independent variable
goodman and Kruskal’s gamma
a measure of association between ordinal level variables
goodman and krskals lambda
a measure of association between on nominal or ordinal level variable and one nominal level variable
interaction
the strength an direction of a relationship depend on an additional variable or variables
measures of association
statistics that summarize the relationship between two variables
multivariate analysis
data analysis techniques designed to test hypotheses involving more than two variables
multivariate cross tabulation
a procedure by which cross tabulation is used to control for a third variable
Proportion reduction in error (PRE) measures
a measure of association that indicates how much knowledge of the value of the independent variable of a case improves prediction of the dependent variable compared to the prediction of the dependent variables based on no knowledge of the case’s value on the independent variable
total variance
a numerical measure of the variation in a variable, determined by summing the squared deviation of each observation from the mean
logistic regression
a nonlinear regression model that relates a set of explanatory variables to a dichotomous dependent variable
logistic regression coefficient
a multiple regression coefficient based on the logistic model
maximum likelihood estimation
a class of estimators that chooses a set of parameters that provides the highest probability of observing a particular outcome
multivariate regression analysis
a technique for measuring the mathematical relationships between more than one independent variable and a dependent variable while controlling for all other independent variables in the equation
multivariate regression coefficient
a number that tells how much Y will change for a one unit change in a particular independent variable, if all the other variables in the model have been held constant
regression analysis
a technique for measuring the relationship between two interval or ratio level variables
regression coefficient
a statistic that tells how much the dependent variable changes per unit change in the independent variable
regression constant
value of the dependent variable when all the values of the independent variables in the equation equal zero
r squared
the proportion of the total variance in a dependent variable explained by an independent variable
