AtlasSession 2L6: Hypothesis Testing and Statistical Testsp.18–24
Alpha error
Fig. 1
Two batches of one GelMA recipe: compressive modulus (kPa), true mean 25, SD 5; and the three-ball bag
Fig. 1. Batch pairs of samples of 10 from one population (no real difference). None run yet.
- Batch pairs so far
- 0
- Looked different by luck
- 0 of 0 (no batch pairs yet: press Play or +1)
- False alarms
- — (no batch pairs yet: press Play or +1)
Sampling Simulator · First look
nothing drawn yet
Level 1 · First look · Lecture 6 · p.18–24
See how pure luck can make us shout 'it works!' when nothing is going on.
Explain alpha (type I, false positive) error as a random error and work out the chance of rejecting a true null by chance alone.
Three-ball bag (the step you are on)
Lecture 6 · p.19–21One red in three; red once is 1/3, twice 1/9, three times 1/27.
One red ball in a bag of three, put back after every draw: red once is 1 in 3, twice 1 in 9, and 3 times running —.