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