Here's why:
* The "o" sound in "robot" is a short vowel sound. It's similar to the "o" sound in words like "hot" or "lot".
* Long vowel sounds are typically associated with a vowel letter followed by a silent "e" or a vowel digraph (two vowels together). For example, "hope", "kite", "boat".
Therefore, "robot" is not a long vowel word.