300 Flashcards

(29 cards)

1
Q

non-parametric alternative: Paired T-test

A

Wilcoxon signed-rank test

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2
Q

non-parametric alternative: Two sample T-Test

A

Mann-Whitney U test

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3
Q

non-parametric alternative: One-way ANOVA

A

Kruskal-Wallis test

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4
Q

non-parametric alternative: Repeated-measures ANOVA

A

Friedman test

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5
Q

non-parametric alternative: Correlation

A

Spearman’s rank correlation

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6
Q

non-parametric alternative: Chi-square test for independence

A

Fisher’s exact test

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7
Q

non-parametric alternative: Simple linear regression

A

rank-based regression

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8
Q

Chi-square contingency analysis test steps and when to use:

A

When you have two or more independent samples with categorical outcomes. (Snakes with or without bands from two different areas).

Write out contingency table

Calculate expected counts - (Row total * column total)/Grand total

With expected value, calculate chi square.

Df = rows - 1 * columns - 1

Chi-square = n(ad-bc)^2/(a+b)(c+d)(b+d)(a+c)

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9
Q

Chi-square Goodness of fit steps and when to use:

A

Test if observed frequencies match a theoretical model - 3:1 mendelian ratio.

Find expected counts

compute chi-square

df= categories -1

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10
Q

One sample t-test steps and when to use:

A

Comparing a sample mean to a known constant
(observed body temp to expected body temp)

find standard deviation and mean.

Calculate t

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11
Q

How to compare means with unequal variance

A

Welch’s T-test

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12
Q

Paired t-test steps and when to use:

A

Compare mean of differences between a pair to null hypothesis value.
(cooling constant of mice, reheated vs fresh)

Find standard deviation and mean of difference between pairs.

calculate T

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13
Q

2 sample T-test steps and when to use:

A

Comparing means of two independent groups.

Need to find s^2 for both groups

pooled variance

SE

Then calculate T using means and SE

Assumptions: Normality in both groups and equal variances

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14
Q

Single factor ANOVA steps and when to use:

A

Comparing means among >2 groups.

Assumes normality and equal variances.

Compute grand mean: sum of all data/N

Compute MS Error and MS group to find F

df Error = N - k
dfGroup = k-1

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15
Q

Correlation

A

Test strength & direction of linear relationship between 2 numeric variables.

Find r and SEr

t=r/SEr

df=n-2

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16
Q

regression

A

Predicting y from x

Linear assumes the relationship can be described by a line.
Logistical is for categorical variables.

find b

find intercept (alpha)

from that get equation for y

Find SEb

t=b/SEb

17
Q

Test to determine if normally distributed

A

Shapiro-Wilkins test

19
Q

Chi-square goodness-of-fit assumptions

A

Independent observatuions
If expected counts are small, use an exact test.
Each observation falls into only one category

20
Q

Chi-square contingency asumptions

A

Data are counts/frequencies
Independent observations
No cell should have 0 expected count
Small counts -> fisher

21
Q

One-sample t-test assumptions

A

Response variable is numerical and continuous
dample is independent and random
Variable is normally distributed in the population

22
Q

Two-sample t-test assumptions

A

Response variable is numerical and continuous
Samples are independent
Both groups normally distributed
Variances are equal, if not - Welch’s t-test

23
Q

Paired T-test assumptions

A

random sample of pairs, the differences are normally distributed

24
Q

ANOVA assumptions

A

All samples are random samples from populations that are normally distributed with equal variance.

25
Pearson Correlation assumptions
Linear relationship between variables for all values of x, y is normally distributed. For all values of y, x is normally distributed w/ equal variance
26
What is the central limit theorem
The sum (or mean) of a large number of measurements randomly sampled from a non-normal distribution is approximately normally distributed.
27
Three features in experiment to reduce bias
control randomization blinding
28
F-test
Used to compare variances
29