PSY 103 Mod 1 Statistics Notes PDF

psy 103 mod 1 Statistics Statistics - range of techniques for analyzing interpreting,displaying,...

psy 103 mod 1 Statistics Statistics - range of techniques for analyzing interpreting,displaying, and making decisions based on data. Describing set of data the Inferential Involved small group > general Descriptive researcher Collected statement for the larger population Psychological statistics Analyze a collection of numerical facts about psychology make conclusions Present. Organize Summarize make use STATISTICAL METHODS that are commonly applied to the analysis of psychological data Data- usually numerical data with no meaningful description Types of variables Variables - character that varies across (nababago), Dependent ( criterion) Independent (causal) Constants - Remains same Outcome - Cause Discrete- No intermediate values (no of child in a family) Continuous - can take any values within given range (height) Categorical - are characterized by categories or groups (gender) Discrete vs Continuous vs Categorical. Scales/Levels of Measurement Nominal-possible values are unordered Ordinal- there is magnitude (values are in order) Interval-no absolute zero Temperature Ratio- has absolute zero. Parametric vs Nonparametric Statistics Parametric statistics - stats based cn distributions and their parameters Assumptions of Parametric Statistics Normal Distribution Random Sampling Interval/Ratio Level of Measurement Homogeneity of Variance Nonparametric statistics- if scale does not meet normal * failed to meet even one criteria of parametric Types research design Statistics and Research Quantitative Qualitative Mixed methods Population - collection of people who could be measured Sample- a representative subset of the population Numerical Descriptive analysis A probability sample is more likely to represent the population (external validity) than a nonprobability sample. Experimental Quasi experimental non-experimental Research design Experimental- causation/ random sampling and assignment I manipulation at IV Sample and sampling methods Quasi-experimental - "experiment-like" / not random sampling / manipulation of IV Probability Non probability Non-experimental- descriptive 1 correlation/ Purposive regression/comparative Random Snowball Stratified Convenience Systematic Incidental Cluster  Psy 103 mod 2 Frequency tables -Used to organize, describe, and interpret data in a more meaningful manner Array-commonly arranged from highest to lowest Simple frequency table - use for large number of observations 2 column table(possible scores| frequency Cumulative frequency (Cf)- from F of the lowest score ) add up Relative frequency-tells us what proportion of the group attained each score Cumulative relative frequency (crf) Cumulative percent frequency (cpf) Graphing your results Bar graph- used for discrete and categorical type of data Histogram - used for continous data line graph- timeline Pie chart (no more than five) use of percentage Grouped frequency distribution - grouping the scores into equal-sized intervals (class intervals) - usually for measurements on an interval/ratio scale Apparent limit that values seen Ina class First lower apparent 60-64 Second upper apparent Real limits (class boundaries) - the lower real limit is.5 less than the lower apparent limit (59.5) - the upper real limit is.5 greater than the upper apparent limit (64.5) * Real limit remove the gaps (for continuous data  Psy I03 mod 3 MCT Measures of central tendency Summarize a sample by single typical value Mean Median Mode Mean- most useful Add and divide W number of data Median - middle of distribution Array and find middle value Unimodal Multimodal mode- the most occurring Array and find mc Bimodal Unimodal -Normal distribution Bimodal-two meaningful modes multimodal-Distribution with move than 2 peaks Positive skewness-Floor effect (mean >median>mode ) Negatively skewed-floor effect (mean