Data Issues

Waves 1 to 7
Data issues - Waves 1 to 7 – February 2019

8 Data issues in Wave 3.5

8.1 Q30B and Q24K

These questions ask how many hours per week the study child spends doing each of the following activities: watching TV, watching DVDs, using the computer, playing games, and listening to music. A total of 20 B and K respondents indicated an unusually large number of hours for some of these activities (that were not able to be corrected through normal editing processes). If the respondent indicated that the child spent more than 40 hours on weekdays doing an activity, these activities were set to missing.

This affected:

  • nine cases for the B cohort and two cases for the K cohort for time spent watching TV on weekdays
  • one K cohort case for time spent listening to music.

If the respondent indicated that the child spent more than 20 hours on a weekend doing an activity, these activities were also set to missing. This affected:

  • six cases for both the B cohort and the K cohort in relation to time spent watching TV on the weekend
  • two B cohort cases and three K cohort cases for time spent watching DVDs on the weekend
  • two B cohort and eight K cohort cases for time spent using a computer on the weekend
  • one B cohort and three K cohort cases for time spent playing a game console on the weekend
  • one case for both the B cohort and the K cohort in relation to time spent listening to music on the weekend.

Care should be taken when using data on media use as there is no provision in the form for parents to report whether the activities were undertaken concurrently. For example, the TV may be on and the child may also be using the computer; therefore, it may be acceptable that some reports of total activities are greater than the total hours in a weekend. However, while watching TV and using a computer at the same time may be plausible, it cannot be clearly determined that this is what is occurring from the responses given.

8.2 Q13B and Q35K

These questions ask for the number of days per week during school term that the study child walks, rides, uses public transport or goes by car to and from school. Although respondents were asked to report the MAIN form of transport each day, some respondents reported multiple travel types.

The question aimed to obtain the main mode of transport used during an average school week to and from school. Therefore, the number of trips to and from school should sum to five each. However, this was not the case for some respondents, as shown in Table 13.

Table 13: Frequencies on Q13B and Q35K
  To school From school
B cohort  
Less than 5 125 132
5 2,694 2,785
More than 5 126 116
Total 2,945 2,901
K cohort
Less than 5 35 77
5 2,739 2,674
More than 5 183 181
Total 2,957 2,932

The cases in which the number of trips to or from school did not add to five have been set to missing. This affected 296 in the B cohort and 319 in the K cohort in total. Two hundred and three B cohort and 157 K cohort cases had this problem for both to and from school. Forty-eight B cohort and 61 K cohort cases had a problem with to school, while 45 in the B cohort and 101 in the K cohort had a problem with from school.

8.3 Q25B/Q26B and Q12K/Q13K

Instructions to skip questions

There were a number of questions where respondents did not follow the skip instructions correctly. Where this inconsistency led to people answering the question who should not have, their data was removed. However, missing data could not be replaced in most cases. This affected the following questions:

Table: Instructions to skip questions
Cohort Question no. Description
B 5 Looked forward to going to school
B 6 Upset or reluctant to go to school
B 8 Teacher informs parent of child's progress behaviour
B 9 How well child gets along with other children
B 10 Quality of education
B 11 Teacher/Parent relationship
B 12 School social capital
B 13 Travel to and from school
B 14 Distance to school
B 15 Provide help with homework
B 16 Experiences before child started school
B 17 Communication with school before child started
B 18 Child's transition to school
K 20 Child began to menstruate

'None of the above' questions

A number of questions provided a 'none of the above' option if none of the other response categories applied. Experience with other self-complete forms shows that it is not uncommon for people to omit ticking 'none of the above'. In general, it could be assumed that many of the responses to questions that had no response categories ticked are in fact 'none of the above'. However, some people may skip questions for reasons that are not readily apparent. In these cases, the item has been left as missing. This affected the following questions:

Table: 'None of the above' questions
Cohort Question no. Description
B 16 Experiences before child started school
B 17 Communication with school before child started
B 27 Sleep problems
B 28 Stressful life events
K 21 Stressful life events

'Yes/No' questions

As for 'none of the above', it seems that some of the missing data for these questions could be explained by respondents for whom the 'no' response was relevant, omitting to tick the 'no' option. The main questions affected are:

Table: 'Yes/No' questions
Cohort Question no. Description
B 33 Family rules
K 6 Family rules about homework
K 7 Special place to do homework
K 28 Family rules

Substantial amounts of missing data

There were some cases in the B cohort (one) and the K cohort (five) that had roughly 90% or more missing data. These cases have been excluded from the raw data files and the final files.