In total, 6000 diverse molecules were selected from PubChem using RDKit's implementation of the MaxMin algorithm based on Morgan fingerprints. Subsequently, CDK Depict , a structure depiction generator based on the Chemistry Development Kit (CDK) , was used to create production-quality 2D images in batches. Each batch of images was then converted into PDF files and they were distributed among the volunteers. Using the chemical structures depictions generated by CDK as a visual template, each volunteer drew the structures on a piece of paper using a black or blue pen or on their tablet using an input device.