Hypothesis testing Flashcards
t-test
Tests for; Produces; H₀; H₁; Reject the null; Format; DoF; Special note
Tests for:
A potential relationship between two means
Produces:
t-value and p-value
H₀:
The means are equal
H₁:
The means are not equal (μ1 > μ2 or μ1 < μ2)
Reject the null:
When p-value < significant value
Format: 2 lists (ALWAYS 2-sampled, pooled)
DoF:
On calculator
Special note:
Make sure the correct symbol is inputted in the calculator (either μ1 > μ2 or μ1 < μ2)
χ2 test for independence
Tests for; Produces; H₀; H₁; Reject the null; Working out exp freq; DoF; Needs; Special note
Tests for:
2 variables are independent
Produces:
χ2-value and p-value
H₀:
The two variables are independent
H₁:
The two variables are not independent
Reject the null:
When either p-value < significant value OR calculated χ2 value > critical value
Format:
Observed and expected numbers in 2 separate tables
Working out exp freq:
calculator does it
DoF:
(rows-1) x (column-1)
Needs:
Two variables
Special note:
Any values less than 5 must be combined with an adjacent table
χ2 GOF
Tests for; Produces; H₀; H₁; Reject the null; Working out exp freq; DoF; Needs; Special note
Tests for:
If data fits a given distribution
Produces:
χ2-value and p-value
H₀:
Data follows given distribution
H₁:
Data does not follow the given distribution
Reject the null:
When either p-value < significant value OR calculated χ2 value > critical value
Format:
Observed and expected in two lists, any values less than 5 must be combined
Working out exp freq:
Multiply probability of each
DoF:
Columns -1
Needs:
A given distribution (ie normal distribution)
Special note:
Exp freq example -
7 9 13 14 [43]
14 12 9 7 [42]
[21] [21] [22] [21] [85]
Working out the expected value for column 3, row 1 -
22/85 x 43/85 x 85 = 11.129
Working out expected frequencies during a χ2 GOF test:
7 9 13 14
14 12 9 7
Observed: Expected:
7 9 13 14 [43] 10.624 10.624 11.129 10.624
14 12 9 7 [42] 10.376 10.376 10.871 10.376
[21] [21] [22] [21] [85]
