Statistics Describe InferGraphs Table Number Estimate Test
Parameter = characteristic of the populationStatistic = Measuredon the sample
Trait or characteristic • Possibility of more than one value: it varies • Values = the possible outcomes of variable • Measured for each case (individual) in sample Usually many variables are measured
Major focus in Research Methods classes.All research is only as good as its measurement
Interested in abstract concepts = constructs • Love, happiness, success, effectiveness • Depression, risk, poverty, hatred, alienation • Birth rate, foreclosure rate Operational definition • What indicates the presence of love, risk, or success? • Exactly what procedures do we use to measure it?
Assign a number to location on the continuum. The number is not exact (e.g., 2.4) Refers to a range of values (here, 2.35 to 2.45)
Four levels • Nominal • Ordinal • Interval • Ratio The statistics we choose for each technique must be chosen according to the scale of measurement of the variable Need to recognize it instantly
All sciences depend on specific analytical methods.Statistics is an integral part of many methods
Two variables are measured to determine thestrength and direction of their relationship.
Measure outcomes Apply treatment to one group, not to another Statistics test whether the differences between groups could happen by random chance.
Independent variable is manipulated by the experimenter Dependent variable is the outcome, also called the control condition Quasi-experiment = groups are not equivalent
See Appendix A for more extensive Math Review.Also “Purple Math” under Stats Success
Omnipresent Work the TUTORIALS in Aplia to gain efficiency How does summation fit into the Order of Operations?
Parentheses Exponents (powers, roots) Multiplication or Division SUMMATION Addition or Subtraction
Learn terms best by using them in meaningful work Practice how to apply definition, not just memorize Analyze research you learn in other courses
Look for as many hidden instancesof statistics as you can find beforethe next class.