# What is the difference between R and ICC?

## What is the difference between R and ICC?

So Pearson’s r will allow the raters to have their own means (with difference b) and for one rater’s ratings to be multiplicatively higher or lower than the other rater’s ratings (by a factor of m). Consistency ICC will allow the raters to have their own means but not to be multiplicatively different.

## What does the ICC mean in R?

Intraclass Correlation Coefficient
Intraclass Correlation Coefficient in R, ICC is used to determine if subjects can be rated reliably by different raters.

How do you read ICC results?

The ICC is a value between 0 and 1, where values below 0.5 indicate poor reliability, between 0.5 and 0.75 moderate reliability, between 0.75 and 0.9 good reliability, and any value above 0.9 indicates excellent reliability .

### Is ICC the same as Pearson correlation?

Like the Pearson correlation, the ICC requires a linear relationship between the variables. However, it differs from the Pearson correlation in one key respect; the ICC also takes into account differences in the means of the measures being considered.

### What is a low ICC?

Like most correlation coefficients, the ICC ranges from 0 to 1. A high Intraclass Correlation Coefficient (ICC) close to 1 indicates high similarity between values from the same group. A low ICC close to zero means that values from the same group are not similar.

What is conditional ICC?

icc() calculates an adjusted and conditional ICC, which both take all sources of uncertainty (i.e. of all random effects) into account. While the adjusted ICC only relates to the random effects, the conditional ICC also takes the fixed effects variances into account (see Nakagawa et al. 2017 ).

## How do you interpret ICC in SPSS?

Run the analysis in SPSS.

1. Analyze>Scale>Reliability Analysis.
2. Select Statistics.
3. Check “Intraclass correlation coefficient”.
4. Make choices as you decided above.
5. Click Continue.
6. Click OK.
7. Interpret output.

## Why is r used for correlation?

Or in other words: R is a correlation coefficient that measures the strength of the relationship between two variables, as well as the direction on a scatterplot. The value of r is always between a negative one and a positive one (-1 and a +1).

What is the value of ICC in R?

The value of an ICC can range from 0 to 1, with 0 indicating no reliability among raters and 1 indicating perfect reliability. The easiest way to calculate ICC in R is to use the icc () function from the irr package, which uses the following syntax:

### When to use intraclass correlation coefficient (ICC)?

Continuous data: Intraclass correlation coefficient. When the variable is continuous, the intraclass correlation coefficient should be computed. From the documentation for icc: When considering which form of ICC is appropriate for an actual set of data, one has take several decisions (Shrout & Fleiss, 1979):

### Which form of ICC is appropriate for the data?

When considering which form of ICC is appropriate for an actual set of data, one has take several decisions (Shrout & Fleiss, 1979): 1. Should only the subjects be considered as random effects (‘”oneway”‘ model) or are subjects and raters randomly chosen from a bigger pool of persons (‘”twoway”‘ model).

How should missing data be omitted from an ICC?

Missing data are omitted in a listwise way. When considering which form of ICC is appropriate for an actual set of data, one has take several decisions (Shrout & Fleiss, 1979): 1. Should only the subjects be considered as random effects (‘”oneway”‘ model) or are subjects and raters randomly chosen from a bigger pool of persons (‘”twoway”‘ model).