I alphabetized the sight words used for preschool, kindergarten, and first grade classes, and I did so because I start off the academic year with blank spaces. I show the students our "word wall", and then I introduce these words to my class and make extension activities for them ("use them in sentences", "find similarities between them", etc.) in centers. It's not best practice to have these just posted up without explaining what they are. Students will better internalize these words and their meanings should you spend some "focus" time doing whole group instruction with them.