Thanks for the comment. I'm not really sure what you mean. The truth table is a way for analyzing statements, not arugments. An arugment is valid if the truth of its premises imply the truth of its conclusion. Here we are just analyzing a single statement. If you were asking whether the satement was a tautology or a contradiction, it is neither, as evidenced by the fact that the last column has both T's and F's in it.
The key is to ensure you have all 8 combination of trues and falses. However, it is useful to arrange them in a standard order so you can compare your solution to others'.
