# Information about statistics and statisticians

Activity Log

January 2012

This activity log reports the projects that Professional Statistical Services conducted during January of calendar year 2012. Unless otherwise specified, all computerized analyses were conducted using SPSS.

 Project Title Description Methods Used Status Graduate statistics and probability course problem set Compute probability mass function (pmf), use pmf to compute means and SDs, compute the cumulative distribution function (cdf), determination of game fairness, compute expected values from pmfs, binomial probabilty problems Knowledge of probability mass functions, cumulative distribution functions, expected value computation Knowledge of game fairness and how to assess it Knowledge of binomial probability computation completed Psychology graduate statistics course problem set Assess normality of distributions, identify outliers, calculate alpha, beta, and alpha-beta effect estimates, factorial ANOVA in SPSS, interpretation of the Levene statistic, write up ANOVA results in APA format. Knowledge of normality testing methods (e.g., Shapiro-Wilk) Calculation of alpha, beta, and alpha-beta sums of squares Factorial ANOVA in SPSS Knowledge of APA format and journal results section conventions completed Psychology graduate statistics course problem set Computation of Cohen's d, computation of power using G*Power, computation of number of subjects needed to obtain specified power to detect a specified effect size as significant, meaning of power, relationship between power, type 1 error, and effect size. Cohen's d computation Use of G*Power Knowledge of relationship betwen power, type 1 error, and effect size. completed Psychology graduate statistics course problem set Identification of difference between descriptive and inferential use of statistics, difference between parametric and nonparametric statistics, difference between internal and external validity, inferences from convenience samples, sums of squares computation, applying normal distribution probabilities, standard error of the mean, choice of t vs. z distribution, test of normality assumption, computation of product-moment correlation, data transformations Knowledge of distinctions between descriptive and inferential statistics, parametric and nonparametric statistics, and internal vs. external validity Knowledge of nature of convenience samples Sums of squares computations Normal distribution probabilities t vs. z distributions Tests of normality assumptions (i.e, Shapiro-Wilk) Product-moment correlation Data transformation to achieve normality completed MBA statistics course problem set Determine sample point probabilities, conditional probabilities, probabilities from contingency tables, determination of independent events, develop probability tree diagram, random sampling using tables and Excel. Probability theory Independence vs. dependence probability trees random sampling completed MBA statistics course problem set Determination of appropriate statistical tests, chi-square tests of differences in frequency distributions, interpretation of frequency distributions, distributional characteristics (e.g., skew, kurtosis), confidence intervals, z-scores, boxplots, scatterplots. z-test for proportions chi-square goodness of fit test moments of distributions z-scores boxplots, outlier identification scatterplots completed MBA Management Science problem set Problems requiring determination of optimal order quantity under various constraints; Knowledge of optimal order quantity computations; Solver for Excel completed Assist in preparation of dissertation proposal Assist in conceptualization of the study; assist in wording of research questions and hypotheses; assist in write-up of methods chapter. Research design skills Data collection skills Analysis methodology knowledge Writing skills completed Analyses and write-up of animal and human clinical trial data on dental products Creating Excel templates for presentation and analysis of clinical trial data for animals and humans comparing the effect of a plaque-reducing agent to a placebo; writing up journal articles on results. Excel formulas Tests of normality assumptions (e.g., Anderson-Darling) t-tests for independent groups Mann-Whitney tests ongoing MBA Management Science problem set Problems requiring computation of internal rate of return, expected value, waiting times, Internal rate of return Expected value Waiting time computation based on Poisson distribution completed Analysis of data from a study of cognitive problem solving strategies Extensive work on creation of data set for analysis, including about 180 separate variable creation commands; tabulation of mean counts and category percentages for many cross-sections of the sample; comparisons of groups using nonparametric tests. Data set creation commands in SPSS Custom tables commands in SPSS Mann-Whitney tests completed Analysis of neuropsychological research data Analysis of a large amount of data collected in a research study; many multi-factorial ANOVAs comparing different groups and subjects under different conditions; many charts and tables. Descriptive statistics ANOVA (multi-factorial) ANOVA (repeated measures) Testing of variables for conformance to parametric assumptions Kruskal-Wallace test Mann-Whitney test completed Graduate statistics problem set Large number of short case problems in statistics, covering hypothesis formulation, univariate and bivariate parametric statistical tests, chi-square, tests of assumptions, nonparametric alternatives to bivariate tests, product-moment correlations, critiques of research designs, and analysis of variance and covariance t-tests (independent and paired) Chi-square Wilcoxon rank sum Product-moment correlation Analysis of variance Analysis of covariance All analyses were required to be conducted in Minitab. completed Graduate statistics problem sets Topics include hypothesis specification, levels of measurement, 2-way ANOVA and correlation Descriptive statistics Frequency distributions ANOVA (multi-factorial) Product-moment correlation completed Medical research study Develop an analysis strategy, analyze data, and write-up Method and Results sections, with tables and figures, for journal article. t-tests ANOVA post-hoc comparisons completed (article accepted) MBA Management Science problem sets Topics include forecasting, control charts (X and R), regression models, and a very difficult linear programming problem. time series incorporating seasonality constructing and interpreting X and R control charts Multiple regression with categorical variables Linear programming using Solver in Excel completed