Are differences between two groups meaningful or did they occur by chance? Be re-randomizing data and using charts, we can both better understand the issues and potentially understand the likely impact.
- [Instructor] A certain school has 200 students.…The students are randomly assigned…to two different groups of 100 students.…Each of the 100 students in the first group is given…a math textbook to learn a certain math concept.…We'll call this Group A.…The second group of 100 students is asked to watch…an online video to learn the same math concept.…We'll call this Group B.…Each group is given 30 minutes to learn the math concept.…
After the 30 minutes are up each of the 200 students…takes an exam with 20 questions.…The students that learn from the online video, Group B,…they had a median test score that was five questions higher…than the students that learned from the textbook, Group A.…Students that watched the video…had a median score of 17 out of 20.…Students that learned the concept from the textbook…had a median score of 12 out of 20.…
Is the video a more effective teaching tool…or did this outcome just happen by chance?…In other words, were most of the students that were better…at math just happened to be assigned to the group…
Author
Eddie Davila
Released
12/19/2016- Working with small sample sizes
- Using t-statistic vs. z-statistic
- Calculating confidence intervals with t-scores
- Comparing two populations (proportions)
- Comparing two population means
- Chi-square testing
- ANOVA testing
- Regression testing
Skill Level Advanced
Duration
Views
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Introduction
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Welcome2m 4s
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1. The Statistics Series: A Look Back and Forward
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2. Small Sample Sizes
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T-statistic vs. z-statistic3m 44s
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3. Comparing Two Populations (Proportions)
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Set up a comparison4m 37s
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Hypothesis testing6m 41s
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4. Comparing Two Populations (Means)
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Set up a confidence interval5m 15s
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Hypothesis testing5m 45s
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5. Chi-Square
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Introduction to chi-square2m 53s
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Curves and distribution3m 48s
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Goodness-of-fit test6m 25s
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6. ANOVA: Analysis of Variance
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7. Introduction to Regression
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What is regression?3m 29s
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The best-fitting line3m 32s
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Conclusion
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Next steps1m 40s
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Video: Visualization (re-randomizing)