Data Transformations

The programs accessed on this page are aimed at systematically transforming a skewed distribution into one that more closely approximates the symmetrical form of a normal distribution. A separate page, entitled Computational Details, describes how these several types of transformations are accomplished.

Procedure:
• Entering Data Directly into the Text Field:T
After clicking the cursor into the text area labeled Raw Data, enter the values for the raw data set in sequence, pressing the carriage return key after each entry except the last. (On a Macintosh platform, the carriage return key is labeled 'Return'; on a Windows platform it is labeled 'Enter.')
• Importing Data via Copy & Paste:T
• Data Check:T
Make sure that the final entry in the list is not followed by a carriage return. (A carriage return after the final entry will be interpreted as an extra data entry whose value is zero. Importing data via the copy and paste procedure will almost always produce an extra carriage return at the end of a column.) After all values for the raw data set have been entered, click the cursor immediately to the right of the final entry in the list, then press the down-arrow key. If an extra line is present, the cursor will move downward. Extra lines can be removed by pressing the down-arrow key until the cursor no longer moves, and then pressing the 'Backspace' key (on a Mac platform, 'delete') until the cursor stands immediately to the right of the final entry.T
• When all raw data values have been entered, click the «Perform» button corresponding to the particular transformation that you wish to produce.

 Raw Data Transformed Data Message Box
 For data with positive skewQ » square root:Q » natural logarithm:Q » inverse (1/X):Q For data with negative skewQ » square root (reflected):Q » natural logarithm (reflected):Q » Inverse (1/X) (reflected):Q

 Proportions in Distribution beyond -2sd -1sd to -2sd mean to -1sd mean to +1sd +1sd to +2sd beyond +2sd TTNormal 0.0228 0.1359 0.3413 0.3413 0.1359 0.0228 Raw Transformed sd = standard deviation

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