Research Methods Exam 3 PDF

Statistics mathematical technique for organizing, summarizing, and interpreting data to answer general research questions. descriptive statistics statistics that summarize the data collected in a study (compute summary values or organize data into tables and figures) frequency statistics number of...

Statistics mathematical technique for organizing, summarizing, and interpreting data to answer general research questions. descriptive statistics statistics that summarize the data collected in a study (compute summary values or organize data into tables and figures) frequency statistics number of scores or occurrences in a variable over time Bar Graph A graph that uses horizontal or vertical bars to display frequency distributions Pie Chart a type of graph in which a circle is divided into sectors that each represent a proportion relative to the data as a whole. Histogram a bar graph depicting a frequency distribution central tendency a number that describes something about the \"average\" score of a distribution mean mathematical average median the middle score in a distribution; half the scores are above it and half are below it mode the most frequently occurring score(s) in a distribution Variability describes the spread of a score (range, standard deviation, scatter plot) range the difference between the highest and lowest scores in a distribution standard deviation amount of variation or dispersion, higher SD means more variability 68-95-99.7 rule in a normal model, about 68% of values fall within 1 standard deviation of the mean, about 95% fall within 2 standard deviations of the mean, and about 99.7% fall within 3 standard deviations of the mean Scatterplot a graphed cluster of dots, each of which represents the values of two variables, can help determine correlation correlation coefficient (r) A single number, ranging from -1.0 to 1.0, that indicates the strength and direction of an association between two variables. Types of hypotheses in stats H1, H2, Between Subjects and Within Subjects null hypothesis the hypothesis that there is no significant difference between specified populations, any observed difference being due to sampling or experimental error. (H0) Two Choices for the Null Hypothesis Reject the Null or Fail to Reject the Null Hypothesis test a procedure for testing a claim about a property of a population, compare results by chance vs actual results Goal of a Hypothesis test rule out chance as a plausible explanation for the results statistically significant an observed effect so large that it would rarely occur by chance, Usually a=.05. p\>.05 fail to reject the null, not statistically significant p\