The Scratch Stroop Effect Game

My project is about the Stroop effect. I want to compare two different representations of the Stroop effect, colors written in a different color ink and shapes with the name of a different shape name on top and see which one is easier to interpret.
Barirah Amin
Grade 8


My hypothesis is that the stroop effect will be more prominent in colors because based on my research, people read words automatically and it is impossible to turn the function of reading off. When they are asked to say the color of the word, looking at the word is necessary which enables the function of reading, yet when they are asked to say the shape drawn, looking at the word written on top is not necessary, making it easier for them to call out the shape.



 The Stroop Effect was named after J.Ridley Stroop who first published this strange phenomenon in English in 1935. The Stroop effect states that when faced with identical and different stimuli there is a delay in reaction time while stating the different stimuli. For example, if a person was shown the word blue written in blue ink, an identical stimuli, they would be able to say the color faster then if they were shown the word blue written in red ink, a different stimuli. 


There are three theories that explain the Stroop Effect.

  1. The Speed of Processing Theory: this theory states that the interference occurs because we read words faster than we name colors.
  2. Selective Attention Theory: this theory states that the interference occurs because naming colors requires more attention than reading words.
  3. Automatic Word Recognition Hypothesis: this theory suggests that people just read words automatically and reading is a function that is impossible to turn off.


Manipulated variable : The manipulated variable in my experiment is the type of Stroop effect that my participants are tested on. 

Controlled Variable: The controlled variable in my experiment is the gender and age of the participants. This is because gender and age affect the Stroop effect.

Responding Variable: The responding variable in my experiment is the reaction times of the participants when shown the two variations of the Stroop effect.



  1. Develop a Stroop Effect Game on Scratch
  2. Ask each volunteer to say the color of the
    word. Repeat for ten words
  3. Record the time taken for them to say the color of all ten words.
  4. Ask each volunteer to say the shape drawn. Repeat for ten shapes. 
  5. Record the time taken for them to say the
    shape drawn of all ten shapes.
  6. Compare your results


  • I noticed that it was a little hard for people to call out the shapes because they didn’t know what the shape was. The most common shape that people got stuck on was a pentagon.
  • I also noticed that people were faster at stating the colors.



My hypothesis was incorrect. The Stroop effect was more prominent in shapes than it was in colors. I think this was because this experiment was the first time they were exposed to the shape Stroop effect, causing a delay in reaction time.



The application for my project is that neurologists can understand that people are slower at recognizing shapes, especially when those shapes are unfamiliar to them, then they are at recognizing colors.  Shapes are processed  by the visual processing centers in the brain. The visual processing centre receives information through the eye. That information is then processed, meaning it is organized and understood  in some way. To remember that information our brain associates that information with previously learned information or new information. We recall or retrieve information from our long or short term memory and express that information.

Sources Of Error

  • The volunteer could have been tired or drowsy while performing the test
  • I could have started my stopwatch early or late
  • I could have ended my stopwatch early or late
  • I could have forgotten to turn on my stopwatch
  • The volunteers could have weak eyesight affecting their ability to see, making them faster at the Stroop effect.


Flowchart symbols-

Google Drawings Logo-

Volunteers of the same gender and age-

Scratch logo-

iPhone Stopwatch-


Internet Browsers-

Example of Stimilus and Response-


Shapes Stroop Effect-

Raz, Amir, et al. "Suggestion reduces the Stroop effect." Psychological Science 17.2 (2006): 91-95. 
Link to access research paper:'

Project Idea-

Information on the Stroop Effect-

More Information on the Stroop Effect-

Different Variations of the Stroop Effect-

The Processing of Shapes-




I would like to thank everyone that particpated in my experiment, as without them I would not have been able to complete my project.

I would like to thank my parents for being supportive throughout my whole experiment.

I would like to thank Google for providing an amazing platform (Google Meet) that I could test my participants on.

I would like to thank Scratch for creating a progamming language that is based on blocks, as it was easy for me to make my game.