3 level data structure and sample size
Posted: Wed Feb 21, 2018 3:59 am
Hi,
We would be grateful for some input if possible.
We are dealing with a three-level nested structure – L1 - 295 people / L2 - 84 houses / L3 - 14 organisations.
Questions:
1. At level 1 the households only have small numbers of people (between 1 - 5). Are there any issues we should be aware of? We are primarily interested in predictors at the household level. Will it be possible to look at slopes across households?
2. The inclusion of a second level in the data (i.e. households) improves the deviance statistic. But, the inclusion of level 3 (organisations) leads to little change (2484 to 2480), which appears to be borderline significant (allowing 1 DF between the models). However the VPC suggests that organisational level contributes roughly 12% of the variance (output below). Can/should we include this third level? If we include it, can we include predictors at this level?
Many thanks in advance,
Shane
We would be grateful for some input if possible.
We are dealing with a three-level nested structure – L1 - 295 people / L2 - 84 houses / L3 - 14 organisations.
Questions:
1. At level 1 the households only have small numbers of people (between 1 - 5). Are there any issues we should be aware of? We are primarily interested in predictors at the household level. Will it be possible to look at slopes across households?
2. The inclusion of a second level in the data (i.e. households) improves the deviance statistic. But, the inclusion of level 3 (organisations) leads to little change (2484 to 2480), which appears to be borderline significant (allowing 1 DF between the models). However the VPC suggests that organisational level contributes roughly 12% of the variance (output below). Can/should we include this third level? If we include it, can we include predictors at this level?
Many thanks in advance,
Shane