Stuart Mann: Regional Scrum Gathering South Africa 2019 Presentation - Cape Town

1. Everything’s Relative
(the brain science behind why we are so much
better at relative rather than absolute estimation)
Stuart Mann / @StuartDMann / @runningmann100

2. Why Estimate?

3. Why Estimate?
We want to create predictability

4. Why Relative Size?

5. How much does
a Hippo Weigh?

6. How much does
a Hippo Weigh?

7. How much does
a Hippo Weigh?
M: 1500 – 1800kg
F: 1300 – 1500kg

8. If a Hippo is a “3", how
much is a Rhino?

9. If a Hippo is a “3”, how much is a Rhino?

10. If a Hippo is a “3”, how much is a Rhino?
White Rhino: 1600 – 2400kg
Male: 1500 – 1800kg
Female: 1300 – 1500kg

11. What Just
Happened
Inside Your
Brain?

12. How much does
a Hippo Weigh?

13. If a Hippo is a “3", how much is a Rhino?

14. An even simpler way to illustrate this…

15. size might not matter but
VELOCITY
does
Stuart Mann / @StuartDMann / @runningmann100

16. Distance2. What is the distance from
your home to the office?
Duration 1 Duration 2
3. How long did each trip
take (in minutes)?
Actual
Speed 1
Actual
Speed 2
4. Calculate your actual
velocity as follows:
distance / time * 60
Speed 1 Speed 2
1. Estimate your average
speed to & from the office.

17. 30km2. What is the distance from
your home to the office?
60 minutes 75 minutes
3. How long did each trip
take (in minutes)?
30km/h 24km/h
4. Calculate your actual
velocity as follows:
distance / time * 60
50km/h 40km/h
1. Estimate your average
speed to & from the office.

18. Thank You
Stuart Mann / @StuartDMann / @runningmann100
Give a man a fish, and you feed him for a day. Teach
a man to fish, and you feed him for a lifetime.
Give a Mann a drink voucher and you’ll quench his
thirst for an hour. Keep buying a Mann beer and
you’ll never get him to shut up.