Отличная статья об исследовании визуальных индикаторов:
https://medium.com/%D1%81%D0%BE%D0%B2%D0%B5%D1%82%D1%8B-%D0%BF%D0%BE-%D0%BF%D1%80%D0%BE%D0%B5%D0%BA%D1%82%D0%B8%D1%80%D0%BE%D0%B2%D0%B0%D0%BD%D0%B8%D1%8E-%D0%B8%D0%BD%D1%82%D0%B5%D1%80%D1%84%D0%B5%D0%B9%D1%81%D0%BE%D0%B2/an-exploration-of-visual-indicators-irl-63046c36edf2
https://medium.com/%D1%81%D0%BE%D0%B2%D0%B5%D1%82%D1%8B-%D0%BF%D0%BE-%D0%BF%D1%80%D0%BE%D0%B5%D0%BA%D1%82%D0%B8%D1%80%D0%BE%D0%B2%D0%B0%D0%BD%D0%B8%D1%8E-%D0%B8%D0%BD%D1%82%D0%B5%D1%80%D1%84%D0%B5%D0%B9%D1%81%D0%BE%D0%B2/an-exploration-of-visual-indicators-irl-63046c36edf2