10. An experiment on TDD
Experiment sold as hands-on exercises
embedded in a training course
Limitationsareplacedondesign
Participantsareprofessionals
butnovicesinthetechnologybeingevaluated
11. TRAINING EXERCISES TREATMENTS
DAY 1 UT Concepts &
Slicing
2 Slicing Exercises BASELINE TASK
(Do It Your Way)
DAY 2 Slicing &
TDD
2 ITL Exercises
1 TDD Exercise
ITL TASK
DAY 3 TDD 1 TDD Exercise TDD TASK
12. Organiza'on Country Date No. of Subjects
Univeristy of Oulu Finland may-14 48
Technical University of Madrid Spain mar-14; oct-14; oct-15 38
University of Basilicata Italy oct-15 20
University of Southern Denmark Denmark jan-16 71
Technical University of Valencia Spain may-14 32
Univeristy of ESPE Ecuador apr-14; apr-15;apr-16 43
Elektrobit/Biaum Finland mar-14 9
Ericsson Finland mar-15 21
FSecure Finland & Malaysia oct-13 31
Mapfre Spain jun-15 14
Paf Finland mar-16 13
PlayTech Estonia mar-14 18
Ecuadorian Army Ecuador Apr-15 22
130 professionals 250 students
15. Recruitment
• Hard to sign up a significant number of par1cipants
– Developer 1me is money
– Number of par1cipants was low in all cases
• 8 -20
• Training was the only carrot that we found
• Company structure has a major impact on recruitment success
– Companies with booked 1me for training were easier to convince
• F-Secure
• Project leader as champion beder than innova1on managers
– PL administers developer 1me
• Mapfre & Playtech
18. @ Paf
Par1cipants
– Planned: 14 subjects
– Real: 13 subjects
– Useful: 8 subjects
• Data removed: 5 subjects
– 4 adended only 1 session
– Group 3 had only 1 subject
The importance of staying on to
perform all experimental tasks was
not well understood
Loosing a group meant that we
were unable to compare all
treatments for several tasks
DAY 1
YW
DAY 2
ITL
DAY 3
TDD
GROUP 1 BSK SS MR
GROUP 2 SS MR BSK
GROUP 3 MR BSK SS
20. @ Ericsson
Planned Design
Expected subjects: experienced in C++, Eclipse, Boost and unit tes1ng
TRAINING EXERCISES TREATMENTS
DAY 1 Tes1ng Tool
Concepts
2 Tool Exercises
1 Mo1va1onal Exercise (ITL)
BASELINE TASK
(Do It Your Way)
DAY 2 Slicing 2 Slicing Exercises CONTROL TASK (ITL)
DAY 3 TDD 3 TDD Exercises TREATMENT TASK (TDD)
TRAINING EXERCISES TREATMENTS
DAY 1 Tes1ng Tool
Concepts
2 Tool Exercises
1 Mo1va1onal Exercise (ITL)
BASELINE TASK
(Do I tYour Way)
DAY 2 Slicing 2 Slicing Exercises CONTROL TASK (ITL)
DAY 3 TDD 3 TDD Exercises TREATMENT TASK (TDD)
Real Design
Subjects: very inexperienced in Boost & unit tes1ng; inexperienced in C++
23. Behavior
• Professionals are less mo1vated than students
– Adendance of a training course <> grading
– Preoccupied with work issues
– Used to flexible schedule
– Young par1cipants more ac1ve and enthusias1c than older ones
– There might be several other psychological issues
• Treatment compliance is lower than for students
– Students appear to be more willing to abide by the rules defined by
instructors
– Professionals tend to have their own ideas about what they expect to
get from the course/experiment
• Professionals might be afraid of being assessed
– Some subjects removed their code
24. Results Reception
• Managers very much welcomed the figures
– They were amazed by the quan1ta1ve informa1on about
development
• Significance was hard to grasp
– They tended to focus on the average and neglected
significance and power
– We tried out different representa1ons
• Charts were very useful
• Repor1ng needs to differ from research papers
– Focus on diagrams rather than numbers
– State the findings in words
– Discuss the consequences of results in their context
25. Means and Error Intervals
Non significant Significant
15.9%
46.4%
22.5%48.3%
58.4%
26. Results Reception
• Managers very much welcomed the figures
– They were amazed by the quan1ta1ve informa1on about
development
• Significance was hard to grasp
– They tended to focus on the average and neglected
significance and power
– We tried out different representa1ons
• Charts were very useful
• Repor1ng needs differ from research papers
– Focus on diagrams rather than numbers
– State the findings in words
– Discuss the consequences of results in their context
27. Impact of Findings
• Some adopted ideas from the experiment (if not
the results)
– To improve their development tools
• EB adopted instruments to monitor developers
• Even when results convinced managers and they
opted to adopt TDD they faced reluctance from
developers
– Concepts from technology transfer are needed