R Studio

Question 1

What are the first commands to put into Rstudio?

Answer 1

Install.packages(‘devtools’)
Devtools::install_github(“mark-andrews/psyntur”)
Library(psyntur)
Library(“tidyverse”)
Library(ggplot2)

Question 2

What does describe function do?

Answer 2

Gets descriptive statistics
Overall mean of the variable for all conditions

Describe(title, mean = mean(variable), stdev = sd(variable))

Describe(title, by =categoricalvariable, mean =mean(variable), stdev =sd(variable))

Does it for each one

Question 3

What does the standard deviation tell you?

Answer 3

Higher standard deviation is more of a range around the mean - bigger variation. A lot of overlapping values.

Question 4

What does the labs() function do?

Answer 4

Adds labels to the pox plot or histogram.

Labs(x = “title”, y = “title”)

Question 5

Function for normal distributions

Answer 5

Plot_normal_sample(1000, mean = 100, sd = 15, bins = number)

For bars in histogram can increase that by increasing number of bins

Question 6

How to look at the distribution of the means in samples ?

Answer 6

Function is:
Plot_repeat_normal_samples( N = 100, n = 10, sd = 15)

N= how many repetitions so 100 in this example
n= each repetition we sample 10 values from the normal distribution.

Question 7

What command to you put for a histogram for normal distributions ?

Answer 7

Hist_repeat_normal_samples()

Question 8

What is sampling variability?

Answer 8

An estimate of the proportion will not be a perfect representation of the true proportion of the population. May be smaller or larger than the average in the population.

Question 9

How to pass it through a deframe and why using a vector helps?

Answer 9

Counts

Question 10

What does sum(counts) tell us?

Answer 10

The total sample size

Question 11

Paired sample t test

T
Df
P-values

Answer 11

T- greater the t value the larger the effect ( less than 1 smaller effect)

Df- how much information the data provides.

P-value- how common the t value is if null hypothesis is true. Needs to be smaller than 0.05- to reject the hypothesis

Question 12

What happens when the size of the SDs are the same as the difference between the means?

Answer 12

The effect size is 1

Question 13

What is the command for a t_test?

Answer 13

t_test(y~x, data = name)

Question 14

How to do you make a box plot ?

Answer 14

Tukeyboxplot(data =name, x = condition, y = condition)