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 [14].
What is an ICC in statistics?
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.
How is ICC calculated?
The ICC serves as a quantitative estimate of this aspect of reliability. Very generally speaking, the ICC is calculated as a ratio ICC = (variance of interest) / (total variance) = (variance of interest) / (variance of interest + unwanted variance).
How do you interpret intraclass correlation?
A flowchart showing readers how to interpret ICC in published studies. Values less than 0.5 are indicative of poor reliability, values between 0.5 and 0.75 indicate moderate reliability, values between 0.75 and 0.9 indicate good reliability, and values greater than 0.90 indicate excellent reliability.
How do you interpret ICC in SPSS?
Run the analysis in SPSS.
- Analyze>Scale>Reliability Analysis.
- Select Statistics.
- Check “Intraclass correlation coefficient”.
- Make choices as you decided above.
- Click Continue.
- Click OK.
- Interpret output.
Is Cronbach’s alpha the same as ICC?
Cronbach’s alpha is identical to the intraclass correlation coefficient (ICC), when the ICC is calculated using either the two-way mixed consistency or two-way random consistency models.
Can you calculate ICC in Excel?
For Example 1 of Intraclass Correlation, we can calculate the ICC as shown in Figure 3. First, we use Excel’s Anova: Single Factor data analysis tool, selecting the data in Figure 1 of Intraclass Correlation and grouping the data by Rows (instead of the default Columns).
How do you use ICC in SPSS?
How does SPSS calculate ICC?
What does a negative ICC value mean?
Negative ICC estimates are possible and can be interpreted as indicating that the true ICC is low, that is, two members chosen randomly from any class vary almost as much as any two randomly chosen members of the whole population.
What is a high ICC?
An intraclass correlation coefficient (ICC) is used to measure the reliability of ratings in studies where there are two or more raters. The value of an ICC can range from 0 to 1, with 0 indicating no reliability among raters and 1 indicating perfect reliability among raters.
Is ICC the same as Alpha?
There are many formulations of ICC and one is equivalent to Cronbach’s alpha when applied to the same data. So alpha is like a special case of ICC. In SPSS when I use ICC(3,1) Two-way mixed single measures (Absolute agreement) the output is accompanied by a Cronbach’s alpha value.
How should I report the ICC in my report?
We suggest that the best practice of reporting ICC should include the following items: software information, “Model,” “Type,” and “Definition” selections. In addition, both ICC estimates and their 95% confidence intervals should be reported. For instance, the ICC information could be reported as such:
What do the numbers in the ICC form mean?
bShrout and Fleiss19defined 6 forms of ICC, and they are presented as 2 numbers in parentheses [eg, ICC (2,1)]. The first number refers to the model (1, 2, or 3), and the second number refers to the type, which is either a single rater/measurement (1) or the mean of kraters/measurements (k).
What is ICC in reliability analysis?
Objective Intraclass correlation coefficient (ICC) is a widely used reliability index in test-retest, intrarater, and interrater reliability analyses. This article introduces the basic concept of ICC in the content of reliability analysis. There are 10 forms of ICCs.
What does the high value of ICC mean?
The high value of ICC shows there is a fair degree of agreement between the judges. Real Statistics Function: The Real Statistics Resource Pack contains the following function: ICC(R1) = intraclass correlation coefficient of R1 where R1 is formatted as in the data range B5:E12 of Figure 1. For Example 1, ICC (B5:E12) =.728.