During last year's General Election 2015, the Sample Count was the real star.

Not only did it accurately predict all the electoral winners of GE 2015, it did so with a margin of error of +/- 2.5 percent.

This is despite the Elections Department (ELD) playing down expectations that the sample count has a 95 percent confidence level and has a margin error of  +/- 4 percent.

Sample count who? Margin of error when? Confidence level what? Here we answer five key questions regarding BE2016 sample count: 

1. What is a sample count?

A counting assistant picks up a random bundle of 100 ballot papers (in front of the candidates and counting agents).

The votes will be added up, with weightage given to account for the difference in the number of votes cast at each polling station.

There are a total of nine polling stations in Bukit Batok.

2. How zhun is a sample count?

Statistician-speak: It has a 95 percent confidence level.

Human-speak: The results has a margin of error of +/- 4 percent. This means we wouldn’t really know which party wins if PAP gets 52 percent of the sample votes, and SDP gets 48 percent of the sample votes.

It also doesn’t mean that the ELD is 95 percent confident that the sample count is correct.

3. Why is there a sample count this time? 

It helps to prevent speculation and misinformation from unofficial sources while counting is underway, before counting is completed and the final election results are announced.

4. Has the ELD done this before? How do we know it’s zhun?

Yes. It is very zhun.

GE 2015 was the first time that sample counts were made public.

Previous counts were conducted in the 2011 presidential election, the 2012 Hougang by-election and the 2013 Punggol East by-election.

In all constituencies except one Single-Member Constituency (SMC), the sample results reflected official results, with a margin difference of less than 2 percentage points.

The only outlier was the three-cornered fight in MacPherson SMC, whose margin of difference is 2.5 percent.

5. When will the results be announced? 

Trick question, only the ELD knows.

At last year's GE, the sample count results for Bukit Batok SMC came in at 9.37pm.

The official results for Bukit Batok was announced at about 1.20am.

Let's hope the candidate can defeat his opponent by more than 4 percent, so that we can all sleep early tonight.

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