Coding and processing time use

Social and Housing Statistics SectionUnited Nations Statistics Division

International Workshop on Social Statistics, Bejing,22-24 November 2010

Coding and processing time use data

How to code and process time use data Coding affects the quality of diary data

and the usability of survey results Most techniques are similar to those for

regular surveys. But focus on issues related to activities

Coding and processing time use data

1) Planning and organizing coding and editing operations

2) Coding activities

3) Aspects of planning and organizing coding activities

Coding and processing time use data

Briefly illustrate with examples from the 2009-2010 French Time Use Survey (EDT)

Consists in a left-behind full diary with 2 interviews

Coding and processing time use data

1) Planning and organizing coding and editing operations

2) Coding activities

3) Aspects of planning and organizing coding activities

Planning and organizing coding and editing operations

Basic tools for coding activities include (Hoffman, 1995):

• Coding instructions• A coding index for classifying activities• A query system

Coding instructions

A document gathering all the stages that the coders should get through

In EDT 2009: 2 documents

Coding index for classifying activities

• Verbatim descriptions are translated into the appropriate codes

• Via keywords• In EDT: SICORE

software. Automatically translates activities as they are stated into codes

Query system

• Useful to update the coding index and the classification

• Clear instructions on when and how coders should raise queries

• In EDT: SICORES stores all the manual codification. Review by the experts and updates from wave to wave

Coding and processing time use data

1) Planning and organizing coding and editing operations

2) Coding activities

3) Aspects of planning and organizing coding activities

Coding of activities

• Assumption: after-coded diary is used as opposed to a pre-coded diary

• Coding consists in determining which group in the classification

• 2 main issues:i) Level of detail in codingii) “Field coding” versus “Office coding”

Level of detail in codingIn general, for classifications, some countries tend to opt

to use less detailed levels because:

• Actual responses would not support coding to more detailed levels

• Not possible to publish results for more detailed groups because of the lack of observation

• Too costly to code a large number of categories

Level of detail in codingBut country experiences have shown that this may not

necessarily be advantageous for classification of activities:

• Good strategy to induce respondents to report activities in more rather than less details

• More information decreases opportunities for coding errors as well as the time needed to find the suitable code for the activity

• The decision to aggregate results should be made at the tabulation stage rather than the coding stage

Field versus office coding

3 strategies:

• Respondent does the coding• Interviewer “Field coding”• Statistical office “Office coding”

Coding by respondent

• Might be considered for leave-behind or self-completed diary

• Higher burden on the respondent mostly if the list is detailed

• Better option: light diary

Field coding• After the face-to face interview (not during)

• Could be computer assisted

• Advantages:i. An interviewer retain in memory more details than

a third person in the officeii. Interviewers gain experienceiii. It simplifies procedures because the diaries can be

encoded directly

Office coding• Most national statistical offices have a

specialized coding unit

• Inconvenient: some distance with the original answer

• Advantage: more controlled environment which contributes to consistency and uniform application of procedures

In French TUS3 actors:

• 1st stage: Field Coding with SICORE. Classification of about 95%

• 2nd stage: Office coding by the coding service of regional directions. >4,9%

• 3th stage: finalization by the person who nationally supervises the survey (Office coding)

Coding and processing time use data

1) Planning and organizing coding and editing operations

2) Coding activities

3) Aspects of planning and organizing coding activities

Aspects of planning and organizing coding activities

Mainly focus on coding rules. 5 scenarios.

Aspects of planning and organizing coding activities

Scenario 1: Coding activities that are not clearly described

Issue: not enough information to code at the lowest level of the classification

Example: “reading” without the type of material (book, periodical…)

Solution: In ICATUS, “not fully defined category”. That use should be minimized

Aspects of planning and organizing coding activities

Scenario 2: Coding of multiple main activities

Issue: Report of more than one activity without differentiating primary from secondary

Solution: Take into consideration whether the activities are performed simultaneously or sequentially and the duration of the activities

Aspects of planning and organizing coding activities

Scenario 3: Coding of multiple main activities

• If the activities are simultaneous and one is likely to be the consequence of the other: this later is coded as secondary

• If the activities are simultaneous and none of them is a consequence: activity mentioned first is the primary

• If the activities are sequential: the one with the longer duration is the primary

• If the activities are sequential and with no clear difference in durations: activity mentioned first is the primary

Aspects of planning and organizing coding activities

Scenario 4: Coding of secondary activities

• It is recommended to have the same set of coding for primary and secondary activities

• However some studies may specify that certain activities are always to be coded as secondary unless they are reported as the only activity

• Example: Eurostat classification specifies that “Lunch break related to employment” should be always coded as secondary

• Code for “doing nothing” should not be used to indicate that there is no second activity

Aspects of planning and organizing coding activities

Scenario 5: Codes for special situations/activities• Main example: travel• An activity classification may categorize according to the

purpose of the travel• Useful tool: viewing a journey as a “circle”

• Example: an errand (trip to store) during lunch break at work

i. Travel to and from work is one circle and have the same purpose (work) and thus have the same code

ii. Trip to store is a circle on its own with the workplace as the starting and ending point and store as the turning point

Conclusion More complication for TUS

than regular surveys because of the time diaries

Some specific issues can be raised regarding the edit checks: overlaps, omitted

activities…

To get an overview, please refer to the UN guidebook