that’s it Goal: ﬁnd out what kind of physical task instructions online Hint: ask them to give you a play by play of what they are doing Try and follow along with your own paper NO helping, even if you could.
for notes. Set the cells of the next column (B) to record the clock time of each entry in A. =IF(A2=“”,“”,IF(B2=“”,NOW(),B2)) Set the cells of the next column (C) to record the diﬀerence between the ﬁrst entry and the current entry =IF(ISERROR(B2-$B$2),“”,B2-$B$2) Fill down (Ctrl-D). Expect to use up to 120 rows for a session. Hide column B. You’ll never need to see it What the formulas look like Auto timestamp! Don’t write this down, it’s on page 104