Title: Confidence intervals
Headings: Confidence intervals
Confidence intervals
How confidence intervals are used
What factors influence a confidence interval?
Why are confidence intervals important?

Content: The researchers are confident that if other surveys had been done, then 95 per cent of the time — or 19 times out of 20 — the findings would fall in this range. The 95 per cent confidence level is used most often in research; it is a generally accepted standard. However, researchers can calculate CIs at any level of significance, such as 90 per cent or 99 per cent. The significance level simply indicates how precise they are willing to be. What factors influence a confidence interval? A narrow or small confidence interval indicates that if we were to ask the same question of a different sample, we are reasonably sure we would get a similar result. A wide confidence interval indicates that we are less sure and perhaps information needs to be collected from a larger number of people to increase our confidence. Confidence intervals are influenced by the number of people that are being surveyed. Typically, larger surveys will produce estimates with smaller confidence intervals compared to smaller surveys.