Do code smells hamper novice programmers?

Do code smells hamper novice programmers?

Felienne Hermans Efthimia

Aivaloglou

Do code smells hamper novice programmers?

Felienne Hermans Efthimia

Aivaloglou

@Felienne

Code smells matter to devs

Do code smells matter to kids?

Do code smells matter to kids?

Sprites

Scripts

Each sprite can have scripts

Do code smells matter to kids?

A simple game

Version N

Version L

Version D

Version D

Version D

Wait what?

Version D

Version D

Version D

Version N

Version L

The experiment

The experiment

61 kids20 x N20 x L21 x D

Hour 1:Scratch Intro

Lesson

Hour 2:Pong experiment

Task types

Task types

Explanation

Task types

“What does this

code do?”

Explanation

Task types Understandi

ng

Task types Understandi

ng

“When have you lost this

game?”

Task types

Modification

Task types

Modification

“Make the game go until

10 pts”

Do code smells matter

to kids?

tl;drYes

tl;drYes

Kids performed significantly better on the non-smelly program

tl;drYes

But, there were differences

between the tasks!

Let’s have a closer look!

Explanation is unaffected by

the presence of smells

Version N

“What does this code

do?”

Version L

“What does this code

do?”

Let’s have a closer look!

Understanding seems affected

more by the Long Method

smell

Version N

“When have you won the

game?”

Version L

“When have you won the

game?”

Let’s have a closer look!

Modification is hampered most by Duplication

Version N

“Make the game go to 10 points”

Version N

“Make the game go to 10 points”

Version D

Version D

Version D