Reaction Index

After each film we ask each audience member to rate it subjectively. The result is Reaction Index (RI) and is a measure of how much an audience "liked" a film. The following information is based on the British Federation of Film Societies (BFFS) notes on the RI.

What is a film Reaction Index?

Every member of the audience at a screening is asked to rate the film or films they have seen on a score of A, B, C, D or E. This is purely their own assessment of how good each film was.

We give out slips of paper marked something like:

A          B          C          D          E

Excellent  Good       Average    Poor       Dreadful

When the votes are collected each A gets multiplied by 100, each B by 75, each C by 50, each D by 25 and each E by zero. These totals are added together and divide by the total number of slips (a + b + c + d + e). The result is the RI.

An Example

At one viewing session the movie My Life Without Me scored:

Rating  A  B  C  D  E

Votes   8 17 13  1  0

If you add up all the votes you see that 39 people expressed their opinion of the film. So if we do the sums:

A  8 * 100 =  800

B 17 * 75  = 1275

C 13 * 50  =  650

D  1 * 25  =   25

E  0 * 0   =    0


Total        2750

Divide by 39 = 70.5

For practical purposes fractions of a percent make no difference so it is usual to round the score up or down to the nearest whole number. In this case 71.

What does it tell us?

At its simplest the scores show which films were liked better than others. It is also worth looking at all the votes to see if it is a movie which split the audience. Sometimes a movie with several As and several Es gets a modest overall RI but is likely to be a better film society bet. Controversy is usually a good stimulus to discussion after the show.

If you study the RIs after a viewing session you can get an idea of how a film is likely to be received by your audience - even if you were not there to see it yourself. What you know is how fellow film society enthusiasts reckoned it.