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LIVE INSPIRED. LIVE TO LEARN. Statistical Analyses: PB&J Peter J. Green Presented 3/14/2014; Missouri JSEHS Symposium. Statistics. Importance for JESHS Difference between interesting and stellar Based on relatively simple math (algebra) Tools exist for computation
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LIVE INSPIRED LIVE TO LEARN Statistical Analyses: PB&J Peter J. Green Presented 3/14/2014; Missouri JSEHS Symposium
Statistics MARYVILLE UNIVERSITY • Importance for JESHS • Difference between interesting and stellar • Based on relatively simple math (algebra) • Tools exist for computation • Basic understanding is possible
The PB&J MARYVILLE UNIVERSITY Descriptive Statistics P-values Correlations T-tests (2 types) ANOVA
Descriptive Statistics MARYVILLE UNIVERSITY Importance of Mean, Standard Deviation MUST be present
Correlation MARYVILLE UNIVERSITY • Measure of association between pairs of variables • Range: -1.00 to +1.00 • Closer to +1.00, stronger the relationship • Closer to 0.00, weaker the relationship • Real world: .30 is a solid correlation
Correlation MARYVILLE UNIVERSITY • Issues • Linear Relationships Only • Influence of Outliers • Both identifiable by a scatterplot • Impact of sample size • Need 20+ to find significance • Determination of p-value
Correlation One individual who is extreme on one or both variables can drastically alter the r value. Eliminate the dot on the upper right, the correlation is – 0.14, but with that data point is + 0.39. (Nolan & Heinzen, 2012). MARYVILLE UNIVERSITY
T-tests MARYVILLE UNIVERSITY • Comparison of 2 means • Technically the difference between 2 means/variability • Larger samples are better (+20) • Impact of outliers
T-tests MARYVILLE UNIVERSITY • Independent Samples T-tests • Data from 2 separate groups • Dependent Samples (Paired) T-tests • 2 pieces of data from the same group • Pre versus post • 2 attitudes, etc. • t (df) = 4.12, p < .05
Analysis of Variance MARYVILLE UNIVERSITY • ANVOA • Comparison of 3 or more means • F (df, df) = 12.32, p < .05
How Do I… MARYVILLE UNIVERSITY • Pearson Correlation • Excel (or Google Spreadsheet) • http://www.gifted.uconn.edu/siegle/research/correlation/excel.htm • SPSS • http://www.youtube.com/watch?v=VOI5IlHfZVE • Contains statistical jargon, but gets the point across; need to have data input first.
How Do I…. MARYVILLE UNIVERSITY • T-tests • Excel • https://www.usciences.edu/biology/bs130/statistics%20for%20biology-t%20test.html • Tails: safest to assume 2 • Type: 1=matched pair; 2=unmatched pair; 3=unequal variance • Does not return a t-value! • Must then use T.INV • OR use Data Analysis – much more information!!! • SPSS • http://www.mhhe.com/socscience/psychology/runyon/spss/ttest.html
How Do I… MARYVILLE UNIVERSITY • T-tests • SPSS • http://www.mhhe.com/socscience/psychology/runyon/spss/ttest.html • Format of data is very different! • Paired = 2 data points in the same row • Independent = needs a grouping variable; all data will be in the same column; one data point per row
How Do I… MARYVILLE UNIVERSITY • ANOVA • Excel: • Single Factor • http://www.excel-easy.com/examples/anova.html • Really nice website for using Excel. • Warning: Generally recognized that results will not be as accurate as SPSS or SAS etc. • Beyond this point we are no longer dealing with PB&J, but are into gourmet breads and hand ground organic peanuts…
How Do I… MARYVILLE UNIVERSITY • ANOVA • SPSS: • One way (Single Factor) • Host of good YouTube videos… • http://www.youtube.com/watch?v=_btBuD3LIsM • Again, moving beyond isn’t PB&J.
PB&J MARYVILLE UNIVERSITY Questions?