Yijue How and Min-Yen Kan
Optimizing SMS Entry (HCII 2005)
7/16
Evaluation Models
•Keystroke Level Model (Card et al. 83)
–Used previously in SMS (Dunlop and Crossan 00, Kieras 01)
–Problem: keystrokes are weighted equally
•
•We developed an Operation Level Model
–Similar to (Pavlovch and Stuerzlinger 04)
–Tie keystrokes to one of 13 operation types
–(e.g.,
– enter a symbol = MPSymK,
– directional keypad move = MPDirK,
– press a different key to enter a letter = MPAlphaK
– press a same key to enter a letter = RPAlphaK