1/25/2023

Discussion of Random Rectangles Activity

The Importance of Randomization

Different types of Bias

Major Statistical Concepts from Section 1.4 Reading

• Treatment versus Control Group
• Placebo and Placebo Effect
• Double-blind Experiment

Step-by-Step Process for Planning an Experiment

• Identify your objective.
• Decide what information to collect.
• Decide how to collect the information.
• Decide how many experimental units are needed.
• Use randomization to assign experimental units to treatments.
• Collect the data.
• Analyze the data.

Gummi Bear Experiments - Conduct an experiment and summarize your results (descriptive stats and visual summaries) in a pdf with the name Design-yourname.pdf. Drop the pdf in your HW folder.

Descriptive Statistics (with data from Data Survey - Open DescriptiveStats.R)

• Measuring Center
  • Mean
  • Median
  • Trimmed Mean
• Measuring Spread or Variability
  • Range
  • Interquartile range
  • Variance
  • Standard Deviation
• Measuring Position
  • Percentiles
  • Five-number Summary
  • Boxplot
  • Standardized Scores
• Identifying Outliers
  • 1.5 x IQR Criterion
  • 2 or 3 standard deviations away from the mean

Class Exercises

The responses on the day 1 data collection survey can be found in the file Google Drive\Stat106-ElementsofStatistics-S2023\!Class-csv-Rscripts\ClassDataS23_Updated.csv. Use this file for the exercises below.

1. Compare the amount of texting completed by varsity athletes with those students who are not varsity athletes using descriptive statistics and at least two different graphical displays.
2. Compare the pulses for cat and dog lovers using descriptive statistics and at least two different graphical displays.
3. Are there any outliers according to the 1.5xIQR criterion for the variable Footlength? PulseRate? Age?
4. Are athletes better at guessing the length of the white (black) string than non-varsity athletes? Explain.

Please read Section 2.2 for class on Friday.