The Weighting Efficiency Report

The Weighting Efficiency Report describes the impact of weighting on your data. The closer your weighting efficiency is to 100%, the more closely your weighted data resembles your actual data, and the better you can consider your weighting.

To view the Weighting Efficiency Report, after you have applied your weight scheme, click the weighting efficiency percentage that appears at the top of the report.

The following table explains the values displayed in the Weighting Efficiency Report.

Weighting Efficiency Report	Values
	Weighting Efficiency A value derived from the following calculation: Weighting efficiency is useful for understanding the impact of weighting on your data. The closer your weighting efficiency is to 100%, the more closely your weighted data resembles your actual data, and therefore the better you can consider your weighting. If weighting is inflating the responses from a particular group unduly, your weighting efficiency will be significantly less than 100%. Reconsider your weight scheme if weighting efficiency is less than 40%. Weighted Base The total number of responses after weighting is applied. Effective Base A value derived from the weight values applied to each participant and calculated using the following formula: The effective base is useful for understanding the impact of weighting on your data. An effective base that is close to the unweighted base indicates weighted data that more closely resembles actual data, and therefore a better weight scheme. If weighting is inflating the responses from a particular group unduly, the effective base will be much smaller than the unweighted and weighted bases. Unweighted Base The total number of responses before weighting is applied. Minimum Weight The lowest weight value associated with a participant's survey responses, indicating how much the participant's survey responses are de-emphasized. For example, if the minimum weight value is 0.11, it means that in your weighted survey data, there is one survey participant or more whose individual response counts as 0.11 responses. In general, it is recommended that your minimum weight be more than 0.5. Maximum Weight The highest weight value associated with a participant's survey responses, indicating how strongly the participant's survey responses are emphasized. For example, if the maximum weight value is 5, it means that in your weighted survey data, there is one survey participant or more whose individual response counts as five responses. In general, it is recommended that your maximum weight be less than 3.

Weighting Efficiency Report

Values

Weighting Efficiency

A value derived from the following calculation:

Weighting efficiency is useful for understanding the impact of weighting on your data. The closer your weighting efficiency is to 100%, the more closely your weighted data resembles your actual data, and therefore the better you can consider your weighting. If weighting is inflating the responses from a particular group unduly, your weighting efficiency will be significantly less than 100%. Reconsider your weight scheme if weighting efficiency is less than 40%.
Weighted Base

The total number of responses after weighting is applied.
Effective Base

A value derived from the weight values applied to each participant and calculated using the following formula:

The effective base is useful for understanding the impact of weighting on your data. An effective base that is close to the unweighted base indicates weighted data that more closely resembles actual data, and therefore a better weight scheme. If weighting is inflating the responses from a particular group unduly, the effective base will be much smaller than the unweighted and weighted bases.
Unweighted Base

The total number of responses before weighting is applied.
Minimum Weight

The lowest weight value associated with a participant's survey responses, indicating how much the participant's survey responses are de-emphasized. For example, if the minimum weight value is 0.11, it means that in your weighted survey data, there is one survey participant or more whose individual response counts as 0.11 responses. In general, it is recommended that your minimum weight be more than 0.5.
Maximum Weight

The highest weight value associated with a participant's survey responses, indicating how strongly the participant's survey responses are emphasized. For example, if the maximum weight value is 5, it means that in your weighted survey data, there is one survey participant or more whose individual response counts as five responses. In general, it is recommended that your maximum weight be less than 3.