Below is the response from a dell agent on TouchCheck (now PalmCheck - Alps):
The PalmCheck™ feature guards against operating the TouchPad with accidental contact. PalmCheck allows the TouchPad to recognize when your palm is resting on it or brushing its surface while you are typing. This will help to prevent unwanted pointer movement or clicks.
If the TouchPad exhibits undesired pointer movement or clicks, increase the PalmCheck setting by moving the slider to the right toward Maximum. If the TouchPad misses intended motions or taps, decrease the PalmCheck setting by moving the slider to the left toward Minimum. You are more likely to experience missed motions or taps.