Attachment 1. Sample size comparison between original and revised experimental design
Within-Subject Design (Original study design, described in 60-day Federal Register Notice)
Table 1 Original Study Design
|
Part-time users (n=16) |
Non-seat belt users (n=16) |
||||||
|
Young driver (n=8) |
Middle-aged driver (n=8) |
Young driver (n=8) |
Middle-aged driver (n=8) |
||||
|
Male(n=4) |
Female (n=4) |
Male(n=4) |
Female (n=4) |
Male(n=4) |
Female (n=4) |
Male(n=4) |
Female (n=4) |
Baseline (A/B) |
4 |
4 |
4 |
4 |
4 |
4 |
4 |
4 |
Treatment A |
4 |
4 |
4 |
4 |
4 |
4 |
4 |
4 |
Treatment B |
4 |
4 |
4 |
4 |
4 |
4 |
4 |
4 |
Research questions |
Sample size for comparison |
Comparison between Baseline A and Treatment A |
n=16 |
Comparison between Baseline B and Treatment B |
n=16 |
Comparison between part-time user and non-seatbelt user |
n=16 |
Comparison between A and B |
n=32 |
Comparison between young and middle-aged |
n=16 |
The interaction effect of System (A/B) *age |
n=16 |
The interaction effect of System (A/B) *belt user group |
n=16 |
The interaction effect of System (A/B) *gender |
n=16 |
The interaction effect of System (A/B) *age*belt user group |
n=8 |
The interaction effect of System (A/B) *age*gender |
n=8 |
Table 2 Revised Study Design
Test Condition |
Part-time users (n=24) |
Non-seat belt users (n=24) |
||||||
Young driver (n=12) |
Middle-aged driver (n=12) |
Young driver (n=12) |
Middle-aged driver (n=12) |
|||||
Male(n=6) |
Female (n=6) |
Male(n=6) |
Female (n=6) |
Male(n=6) |
Female (n=6) |
Male(n=6) |
Female (n=6) |
|
Baseline A |
3 |
3 |
3 |
3 |
3 |
3 |
3 |
3 |
Treatment A |
3 |
3 |
3 |
3 |
3 |
3 |
3 |
3 |
Baseline B |
3 |
3 |
3 |
3 |
3 |
3 |
3 |
3 |
Treatment B |
3 |
3 |
3 |
3 |
3 |
3 |
3 |
3 |
Research questions |
Sample size for comparison |
Comparison between Baseline A and Treatment A |
n=24 |
Comparison between Baseline B and Treatment B |
n=24 |
Comparison between part-time user and non-seatbelt user |
n=24 |
Comparison between A and B |
n=24 |
Comparison between young and middle-aged |
n=24 |
The interaction effect of System (A/B) *age |
n=12 |
The interaction effect of System (A/B) *belt user group |
n=12 |
The interaction effect of System (A/B) *gender |
n=12 |
The interaction effect of System (A/B) *age*belt user group |
n=6 |
The interaction effect of System (A/B) *age*gender |
n=6 |
Table 3 Additional Cost to Implement Revised Study Design
ID |
Description |
Cost Estimate |
1 |
Cost increase in labor charges due to increased subject sample size and engineering support (i.e., increased labor in vehicle installation, data maintenance & download, server maintenance, subject recruitment and data analysis) |
$84,330.24 |
2 |
Cost increase in research supplies (i.e.; vehicle insurance cost, gas and instrumentation) |
$21,934.00 |
3 |
Subject fees ($90/subject * (16 more subjects+8more drop outs) |
$2,680.00 |
4 |
OEM Costs (i.e., extended vehicle rental period |
$12,886.80 |
5 |
Indirect costs on research supplies and subject fees |
$13,594.34 |
TOTAL |
$135,425.38 |
|
| File Type | application/vnd.openxmlformats-officedocument.wordprocessingml.document |
| Author | GarayL |
| File Modified | 0000-00-00 |
| File Created | 2021-01-24 |