Statistics

Question 1

Explain the criterias of a chi-squared ( ) test (DE: Chi-Quadrat-Test)

Answer 1

The chi-squared test is a statistical test to find out if the difference between observed categorial data and expected data is small enough to be due to change.

This test can be used:

• for categorial data
• where there is a strong biological theory that we can use to predict expected values.
• the sample size must be relatively large.
• only raw data counts, not percentages or ratios, can be used.
• there are no zero scores.

Question 2

Steps to conduct the chi-squared test

Answer 2

1. for example cross flowers and look at their F1 generation
2. count the actual outcome of colours
3. use the formula: N= observed numbers, n=expected numbers
4. look up the chi-square value in a distribution table
5. if > 0.05p accept the null hypothesis
6. if < 0.05p reject null hypothesis

Question 3

Was ist Nullhypothese?

Answer 3

Häufig sagt die Nullhypothese aus, dass kein Effekt bzw. Unterschied vorliegt oder dass ein bestimmter Zusammenhang nicht besteht.