study of environments to support e- learning in uk further and ... - Jisc

Environments to support e-Learning In UK Further and Higher Education
Weighting
17. As the previous section shows, there was little, if any, response bias in the achieved
sample apart from the HE/FE split. The results needed adjusting to correct for the better
response rate among HE institutions so that the data did not over-represent views of the HE
sector. Without such correction the conclusions drawn from the data would have been
skewed towards the situation in HE institutions. . It was recommended and accepted by the
project Reference Group that all other variables were left as they are – the more the data are
weighted the greater the impact on sampling error.
18. To adjust the data by type of institution (HE/FE) the following weights were applied to the
data based on the expected number of returns that would have been received with an equal
response rate across FE and HE institutions:
FE
HE
Proportion of universe 72% 28%
Expected number based on 235 returns
169 66
assuming equal response rates (a)
Actual number of returns (b) 150 85
Weight to be applied (a/b) 169/150 = 1.1267 66/85 =0.7765
19. Thus the number of FE institutions in the data were weighted up to 169 and the number
of HE institutions were weighted down to 66. The effect of this is that the weighted data
reflects the balance between FE and HE institutions that would have been the case if there
had been an equal response rate. Put simply, the weighted data reflects the true balance
between FE and HE institutions.
20. In the previous survey (2003) there was no real difference in the response rates between
FE and HE institutions, and so the data were not weighted. However, both sets of data are
directly comparable, precisely because of the weighting applied to the 2005 data.
Data in this report and spreadsheet
21. The numbers (absolute values) in the spreadsheet (available on request from JISC) have
all been rounded up or down to integer values, after applying the weighting factors. This can
cause slight variations in numbers of respondents and can affect subsequently derived
percentages, depending on the distribution of answers.
22. The rounding issue particularly affects instances at the margins (small number of cases
or small base) - the smaller the number of cases and/or the base the more likely a difference
between the percentages in the excel resource and alternative calculations based on
fractional absolute values or before weighting the values.
23. Where applicable in the Survey Evidence section of this report, tables include rows
showing the base (N) from which percentages are calculated. These are the weighted
number of respondents, rounded to the nearest integer value for all institutions combined
(Total) and also for each type of institution (FE, HE pre-92, HE post-92, HE colleges) and for
all HE.
24. In summary:
• The calculation base in the tables in this report also shows weighted data, rounded to
the nearest integer value.
• The percentages of respondents are based on these weighted, rounded results.
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