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Cronbach’s Alpha is a measure of internal consistency for a set of items or questions used to measure a specific construct. In order to calculate it in Google Sheets, you would first need to enter the data for each item or question into separate columns. Then, you can use the formula “=CronbachAlpha(range)” to calculate the Alpha value for your data. This formula takes the range of your data as an input and returns the Alpha value, which can range from 0 to 1, with higher values indicating higher internal consistency.
Chronbach’s Alpha is a way to measure the of a questionnaire or survey.
Cronbach’s Alpha ranges between 0 and 1, with higher values indicating that the survey or questionnaire is more reliable.
The following step-by-step example explains how to calculate Cronbach’s Alpha in Google Sheets.
Step 1: Enter the Data
Suppose a store manager wants to measure overall satisfaction among customers.
She decides to send out a survey to 10 customers who can rate the restaurant on a scale of 1 to 3 for various categories.
First, let’s enter the data that contains the survey responses for each of the 10 customers:
Step 2: Calculate Standard Deviations
Next, we will calculate the standard deviation of values in each column.
To do so, type the following formula into cell B12:
=STDEV(B2:B11)
Then click and drag this formula to the right to cell E12:
Step 3: Calculate Cronbach’s Alpha
Next, we’ll type the following formula into cell B14 to calculate Cronbach’s Alpha:
=(COUNTA(B1:D1)/(COUNTA(B1:D1)-1))*(1-(SUMSQ(B12:D12)/(E12^2)))
Cronbach’s Alpha turns out to be 0.7734.
The following table describes how different values of Cronbach’s Alpha are usually interpreted:
| Cronbach’s Alpha | Internal consistency |
|---|---|
| 0.9 ≤ α | Excellent |
| 0.8 ≤ α < 0.9 | Good |
| 0.7 ≤ α < 0.8 | Acceptable |
| 0.6 ≤ α < 0.7 | Questionable |
| 0.5 ≤ α < 0.6 | Poor |
| α < 0.5 | Unacceptable |
Since we calculated Cronbach’s Alpha to be 0.7734, we would say that the internal consistency of this survey is “Acceptable.”
Additional Resources
The following tutorials provide additional information about Cronbach’s Alpha: