2×2 Contingency Table
Each bootstrap sample redraws
Treatment
and
Control
separately,
with replacement
, keeping the group sizes fixed.
Survived
Didn't Survive
Total
Treatment
—
Control
—
Total
—
—
—
Observed difference of proportions
p̂
T
− p̂
C
=
—
Number of bootstrap samples
0
Show
% CI
One Bootstrap Sample
100 Bootstrap Samples
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Apply Table
Treatment
Original sample
⇣ draw n
T
=
—
with replacement ⇣
Bootstrap sample
p̂*
T
= —
Control
Original sample
⇣ draw n
C
=
—
with replacement ⇣
Bootstrap sample
p̂*
C
= —
Bootstrap p̂*
T
− p̂*
C
:
—
Survived
Didn't Survive
Bootstrapping the Data
Rows are copied from the original data at random. Some rows get picked more than once, others not at all.
Original data
Row
Event
Times picked
Bootstrap sample
Draw
Copy of row
Event
Bootstrap samples:
0