Reporting Data: Numerical

Question 1

What are the two rules we adhere to during hypothesis tests?

Answer 1

1. Must Report exact p-values
   -Never use inequalities(e.g., p = 0.125 vs p > 0.05; p = 0.012 vs p < 0.05)
   -unless p is very small(e.g., p = 0.0000001 can be shown as p < 0.001)
2. Must co-report that affect p-values
   -Sample size (e.g., n = 25)
   -Effect size (e.g., differences in means)
   -Precision (confidence intervals)

Question 2

Bright-line threshold?

Answer 2

It is p<0.05

A bright-line rule (or bright-line test) is a clearly defined rule or standard, composed of objective factors.

Question 3

What is an alternative to bright-line hypothesis?

Answer 3

Another approach is to let the reader interpret the result

Question 4

CI relationship to Precision?

Answer 4

CI is wide and thus decreases precision

CI is narrow and thus increases preciison

Question 5

Three ways to report results?

Answer 5

1. Test Statistic(t-test)
2. Analysis of variance(ANOVA)
3. Simple Linear Regression

Question 6

What kind of errors does Bright-line analysis bring?

Answer 6

“Bright-line” analysis brings in type I and type II errors

Question 7

Type I error?

Answer 7

When the null hypothesis is true, and you reject it

Question 8

Type II error?

Answer 8

When the null hypothesis is false, and you fail to reject it

Question 9

Probability of type I/II error to satistical significance?

Answer 9

Probability of a Type I error is equal to the level set for statistical
significance

Probability of a Type II error is dependent on the statistical power

Question 10

Accuracy vs Precision?

Answer 10

Image result for accuracy vs precision
Precision and accuracy are two ways that scientists think about error. Accuracy refers to how close a measurement is to the true or accepted value. Precision refers to how close measurements of the same item are to each other.

Question 11

What is precision as high as?

Answer 11

Precision is only as high as that of the instrument used to make the measurement

Question 12

When is precision inflation seen?

Answer 12

Precision “inflation” often seen when making calculations

Question 13

What is precision limited by?

Answer 13

When making calculations, precision is limited by the instrument with the lowest precision

Question 14

What do we limit the precision to?

Answer 14

Limit the level of precision to what is useful to the reader

Question 15

Reporting results and SI units?

Answer 15

Use SI units unless there is a historical unit that is used by convention

Question 16

Reporting results and large numbers?

Answer 16

Do not split large numbers using commas

Question 17

Reporting results and commas/decimals?

Answer 17

Do not use commas instead of decimal places

Question 18

Reporting results and summary measurement?

Answer 18

Indicate how summary measures are presented

Question 19

Anatomy of a good figure for a continuous vs continuous scale? SCATTER PLOTS

Figure Heading
Legend
Axis
Axis Scale
Axis length
Key site

Answer 19

Have no figure heading

The legend goes under the figure

Use appropriate axis labels with measurement units

Use the appropriate axis scale. It should not be too cluttered.

Set axis length to avoid too much white space

Key within the plot area(unless unavoidable) or directly label the data

Question 20

Anatomy of a good figure for a continuous vs categorical scale? BAR CHARTS

Plot to use
Figure head position
App for box-and-whisker plot

Answer 20

Box-and-whisker plot

Positioned below

Ms Excel is useless at drawing box-and-whisker plots. Rather use the free app: poltr

Question 21

Should we use dynamite plots for bar charts

Answer 21

NO

They hide important information

Question 22

When do use bar charts?

Answer 22

For categorical scale: Frequency or proportion plots

Question 23

What should you use when you are trying to get across exact figures?

Answer 23

Choose a table over a figure

Question 24

Anatomy of a good table?

Vertical Lines
Horizontal Lines
Information in column
Extra information
Title
Numbers

Answer 24

No vertical Lines

Few horizontal lines. No horizontal lines in body

Always put things you want to compare in columns

Extra information must be put in the footnote under the table

Put the short title at top of the table

Rightly justify numbers. Do not use commas or non-divisible figures if not necessary