Checking whether the protocol was followed: gender and age 51

Transcription

1 Checking whether the protocol was followed: gender and age 51 Session 4: Checking whether the protocol was followed: gender and age In the data cleaning workbook there are two worksheets which form the basis of our checks on Gender and Age entries, Gender Check and Age Check. We start with Gender Check. The protocol demands that approximately equal numbers of males and females are tested in each school. Deviations from this should be recorded in the workbook. Above you see an example of the Gender Check table for a mapping survey. From each school 50 pupils were tested. The first school was a mixed gender school and from each gender 25 pupils were sampled. The second school was a uni sex school and the sample consisted of 50 girls. In both cases the protocol was followed (hoping that a boys only school will counter balance the girls only school). Demonstration Gender Check 1. Open the file Session_4.xlsx and click on the tab of the first worksheet Demo Preparation of the table: hide the columns not needed, format the headings in the first row of the table, insert a column with observation numbers. 3. As a little preliminary check put the cursor in the first row of the Variable Sex and press Ctrl to check for missing values. This hot key will set the cursor at the end of a block. [Cabs Ctrl will highlight the column until the end of the block] 4. We now create a pivot table which shows the number of boys and girls for each school. Highlight the columns Sex, Age, and SchoolCode as shown on the right. 5. Click PivotTable on the Insert Ribbon.

2 Checking whether the protocol was followed: gender and age The following window appears. The field Table/Range: shows the cell range you have highlighted in step 2. In the lower half of the window a destination for the pivot table can be chosen. For this example I clicked the cell O6 on the first worksheet Demo 1. Click OK. 7. The window on the right appears. Drag the variable names into the Pivot Table Definition table as shown on the right. Click on the triangle next to Sum of Sex and click Value Field Settings 8. The window below appears. Under Summarize value field by highlight Count and click OK.

3 Checking whether the protocol was followed: gender and age 53 The pivot table now should state the number of girls and boys in each school (1, 2, 3) along with the total numbers. SchoolIDs Copy the first three columns into the Data Cleaning Workbook. 9. To determine the Total Number of Pupils an % of pupils female in the Data Cleaning workbook use formulas: B7 D7 E7 Now you Open the data3.xlsx file from the last session and do the checking of the variable Sex. Transfer your findings to the Data Cleaning Workbook and save the workbook. Save the cleaned data as data4.xlsx.

4 Checking whether the protocol was followed: gender and age 54 Demonstration Age Check 1. Open the file Session_4.xlsx and go to the worksheet Demo 2 2. Highlight the columns Age, and SchoolCode and create a pivot table with the settings shown on the right. You should get the table below Count of Age Column Labels Row Labels (blank) Grand Total Grand Total The observation with the age appears to be a dummy entry. Check the other values of this observation and decide whether you want to remove this whole observation. The ages 0 and 99 might also be dummy entries or a mistyped entry. Check the other values of this observations and decide if you either want to only delete the age values and mark them as missing values or if you want to delete the whole observations. 4. Copy the respective parts of the pivot table into the Data Cleaning Workbook. If necessary adjust the age range in the workbook to the age range of the data. Total Number of Pupils = sum( < the whole age range we sampled including the missing values > ) Number of Pupils in Protocol = sum( < the age range from the protocol > ) % of pupils in protocol = <# pupils in protocol > / <total # pupils > Now you Continue your work on the data4.xlsx file by checking the variable Age. Transfer your findings to the Data Cleaning Workbook. When you are done save your data as data 4 and save the data cleaning workbook.

5 Checking whether the protocol was followed: gender and age 55 Optional Task To check the ages one also can create a visualisation of the distribution of the age values, e.g. a histogram. For this you need a pivot table which has the ages as row names 1. Create a pivot table similar to the one shown below. 2. Highlight the whole pivot table. Activate the Insert Ribbon and click the button for a Column Diagram. Choose the first 2 D Column Diagram: You should get a get a diagram similar to the one shown on the right. The diagram shows the number of pupils for each age. For each school a differently colour bar is used. Click on the triangle on the SchoolCode button on the right and select a school. Do the same with the Age button on the bottom left.