At one extreme, a researcher might have many (often thousands) of nodes embedded in the same network, and construct a valid comparison group using similar nodes embedded in a different part of the network to the treated node.
These conditions are important for verifying that the untreated area was a valid comparison group for use in statistical analyses.
Third, we did not directly compare web-based training with non-computer instruction (media-comparative research) because it was logistically impossible to have a valid comparison group considering the limited time frame we had at our disposal.
If this proves to be the case, we suggest the creation of a large-scale cohort of elderly patients with ESRD who opt for conservative management to create a valid comparison group to the USRDS database on HD patients.
Therefore the valid comparison group for assessment of prognosis in women with interval breast cancers is non-screen detected cancers among women not invited to mammography screening, which are unaffected by the biases that screening entails.
Although studies based on randomised trials have a valid comparison group, chance could explain the inconsistent findings because the sample sizes in all the studies were limited (<100 interval cancers).
Thus, the purpose of this study was to evaluate whether the FSS-7 demonstrates a similar item hierarchy across three chronic illness groups (MS, stroke and HIV/AIDS) to ensure valid comparisons between groups and provide further evidence of internal scale validity.
The present study evaluates whether the Fatigue Severity Scale 7-item version (FSS-7) demonstrates similar item hierarchy across people with multiple sclerosis, stroke or HIV/AIDS to ensure valid comparisons between groups, and provide further evidence of internal scale validity.
Since mixed households are by definition couples, we limit our investigation to couples in order to make valid comparisons across groups.
