00:00does using the Fibonacci series for

00:02estimating improve the accuracy of those

00:05estimates that's the question we're

00:07going to be looking at today and stick

00:09around to the end to get your hands on

00:11this free agile estimating cheat sheet

00:15my name is Gary Strom welcome to

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00:28miss a thing if you've been following

00:31along with this series on agile

00:33estimating you'll have got the message

00:35by now that estimating is hard but some

00:39estimates are much easier than others

00:42we've talked previously about estimates

00:45of absolute size versus estimates of

00:49relative size how heavy is this is a

00:53hard question which of these is heavier

00:56is an easy question why is it an easy

00:59question well it's because there's a

01:02large difference we assume in the white

01:05of these two when I say difference is

01:07that the absolute difference or the

01:10relative difference which of these two

01:12coins is heavier which of these two

01:15bridges is heavier I hope that answers

01:19it's not the absolute difference that's

01:21important it's the relative difference

01:24hold on a second one there supposed to

01:26be an episode on the Fibonacci series I

01:28think it's time we rolled it in actually

01:31let's build it from scratch the first

01:34two numbers are 0 1 1 and to get the

01:37third we add the first two together 0

01:39plus 1 is 1 and we carry on adding pairs

01:43of numbers 1 plus 1 gives us 2 1 plus 2

01:51two plus three gives us five and so on

02:0434 55 89 what's interesting in this

02:11series is the gaps between the numbers

02:14not the absolute gaps the relative gaps

02:19the relative gap between these two is oh

02:23that's infinite yeah that one's a little

02:25bit large let's move on

02:27the relative gap between these two is

02:3866.6 recurring percent 60%

02:45sixty two point five percent sixty one a

02:49bit percent almost sixty two percent

02:52sixty one point eight sixty one point

02:56eight after some craziness at the

02:59beginning of the series the relative gap

03:01between the members of the series

03:03settles down to around 60 Warren and a

03:07bit percent let me see if I can

03:09demonstrate that to you a little more

03:10visually here are the first few 0 1 1 2

03:153 5 ah yeah now we're at space so I'm

03:20gonna zoom out round about sixty percent

03:23and there's the 8 zoom out another 60

03:29there's the 13 zoom out again 21 zoom

03:3634 zoom out again 55 zoom out one last

03:4289 I hope you can see that although the

03:46bars are getting skinnier as we zoom

03:48further and further out the relative

03:50size between this one and this one stays

03:55pretty well constant

04:00the reason that the scale works so well

04:02for estimating is that it encourages us

04:05to stay in the realm of easy estimates

04:08it encourages us to stay with relative

04:11estimates to say in slightly different

04:14terms if we are estimating two things

04:16and their sizes their relative sizes are

04:20not sufficiently different then we

04:23consider that they both have the same

04:25size which brings us right back to the

04:29question that we started with today does

04:32the Fibonacci series lead to more

04:35accurate estimates I think the answer

04:38has to be no if anything what it does is

04:41protect us from attempting to make

04:44accurate estimates it keeps us in the

04:46realm of making rough or broad estimates

04:51so I'm curious do you use the Fibonacci

04:54series for your estimate I'd love to

04:57know let me know in the comments below

04:59and finally today there's the small

05:01matter of the cheat sheet that I

05:03mentioned at the beginning the agile

05:06estimating cheat sheet you'll find a

05:08link in the comments below click the

05:10link follow the instructions and it's

05:12all yours thank you very much for

05:15watching if you enjoyed this episode

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05:21for a brand new episode each and every

05:24Wednesday look forward to seeing you

05:26next time cheers for now