Intro to Statistical Tools: R vs. PSPP

Title

Intro to Statistical Tools: R vs. PSPP

Files

Download R-v-PSPP Quiz Solutions.pdf (44 KB)

Download RvPSPP_Workshop-RstudioScript.R (668 B)

Description

A simple example of hypothesis testing using R vs. PSPP – a free alternative to SPSS! See comments for download links, sample question and quiz.

Loading...

Media is loading
 

Publication Date

Spring 2020

City

New Orleans, LA

Disciplines

Online and Distance Education | Statistics and Probability

Comments

Today’s question:

A researcher would like to examine the effects of humidity on eating behavior. Laboratory rats normally eat an average of mu = 21 grams of food each day. The researcher selects a random sample of 16 rats and places them in a controlled atmosphere where relative humidity is maintained at 90%, predicting that humidity will affect food consumption. The daily food consumption scores are as follows:

14,18,21,15,18,18,21,18,16,20,17,19,20,17,17,19

Is this finding statistically significant with an alpha (significance level) or 5%?

First we make our null hypothesis:

H0: mean at 90% humidity = population mean

Can we reject this null hypothesis? How do we answer this question using R and PSPP to conduct a 1-sample t-test? See video for solution!

=== Install links ===

R: https://mirror.las.iastate.edu/CRAN/

RStudio: https://rstudio.com/products/rstudio/download/

  • Install R first, then Rstudio. Open Rstudio

PSPP: https://www.gnu.org/software/pspp/get.html

=== R vs. PSPP Quiz ===

1) What are the differences between the variable tab and the data tab in PSPP?

  1. Variable tab changes while data tab does not
  2. Variable tab lists your variables while the data tab shows the values
  3. Variable tab is not needed – we only need to know the data
  4. They are the same

2) What needs to be done in PSPP before adding real data?

  1. You need to calculate your mean
  2. You need to calculate your standard deviation
  3. You need to name your variable in the variable tab
  4. Nothing – just start adding data

3) Given an increase in our number of samples – but no change to the mean and standard deviation of the samples – what will happen to your 95% confidence interval?

  1. No change
  2. It will increase (expand), since n increases
  3. It will decrease (narrow), since you will be more certain in your results

4) Which number is equal to 2.433e-05

  1. 2.43%
  2. 0.00243%
  3. 0.0000243%
  4. 2433.05

5) What advantages do R and PSPP have over other software?

  1. Both are free and open source
  2. They work on all operating systems (Windows, mac, linux)
  3. They provide different approaches to similar problems, with different advantages
  4. All of the above!

Intro to Statistical Tools: R vs. PSPP

Share

COinS