What is an alternative hypothesis?
PICTURE THIS: DATA SPLIT
Fit on train, tune on val, report on test once.
Simple meaning
The alternative hypothesis is the claim you hope the data support, such as a real lift in conversion.
WHY — Hypothesis Testing instead of guessing?
Why interviewers care about Hypothesis Testing:
people who only read docs from people who shipped.
and tied to Data Science work.
Name the idea, why it exists, then one short example.
End with when you use it and one common pitfall.
STEPS — What happens step by step?
Before you speak the answer, walk the interviewer through these steps:
- 1The alternative hypothesis is
the claim you hope the data support, such as a real lift in conversion.
- 2It can be two-sided
(any difference) or one-sided (an increase only).
- 3Hypothesis tests do not
prove the alternative true
- 4they only assess whether
the null is implausible.
- 5Common mistake
What juniors usually get wrong.
- 6Close
When you pick this over the alternative.
EXAMPLE — See it in action
Here's a short line you can speak, broken into clear beats:
Note: Adapt this scaffold to your own project — keep it under 60–90 seconds.
Key takeaway
The alternative hypothesis is the claim you hope the data support, such as a real lift in conversion. It can be two-sided (any difference) or one-sided (an increase only).