Household and Individual Questions

It is important to understand the difference between household and population questions, as there are no software restrictions in applying either household or population weights to the data. This may lead to inaccurate interpretation of results.

Information provided by respondents for both the telephone and mail-back questionnaires, is most often about their personal behaviour:

• Which newspapers they read?
• Whether they use the Internet?
• Where they have gone on vacation?
• Whether they own a cell phone?

However, there are some questions for which respondents provide information about their households:

Which vehicles are in their households?
Future purchase intentions of various products?
Where do they shop for groceries?

Population and Household Weights

• Population Weights

The data provided by respondents about their personal behaviour and preferences is used to project to the population of all Adults 18+ in a specific geographical area or market. For example, a certain proportion might read a particular newspaper or intend to purchase a cell phone in the next 12 months.

• Definition of Population Weights:

refers to the selection probability of the interviewed person. This weight is used for all the questions that are related to the interviewed person and cannot be generalized to the household level.
 

• Household Weights

Data is collected on behalf of an entire household; the data is projected to all households in the market. For instance, certain proportions of all households have a particular model of car or intend to purchase a VCR in the next year. In such cases, where the base is households, the household weight must be selected when doing runs on software such as IMS or Telmar Harris.

• Definition of Household Weights:

refers to the selection probability of the interviewed person in dependence of other household members. This weight is used for questions related to the household (regardless the number of persons in the household).
 

The table below illustrates the use of Household and Population weighting.

Users need to be aware of whether they are examining household or individual questions to understand how to access the correct information. The user should select the appropriate weighting option, either population or household, when using software (e.g. IMS or Telmar Harris).

How To Find Out?
1. Software Supplier Electronic Codebook
2. Study Guide
3. NADbank Study Codebook -Identified by (HH) in the software