IU's schedule has been bad to be certain.

They have played one opponent that currently has a winning record, 6-5 UW, who they defeated pretty soundly back in week 9 of the season by the score of 31-17.

Digging a little deeper into their season you can find a couple of crazy stats due to the lack of good opponents faced.

When you look at long scrimmage plays on a national level IU ranks highly in both 10+ yard plays gained and 10+ yard plays allowed.  IU is 22nd with 164 offensive plays of at least 10 yards, OSU has 161.  IU is 5th nationally with only 96 plays of at least 10 yards allowed by their defense, OSU is even better at 89 allowed.

When you look at those stats against teams with winning records you see how bad IU's schedule has been. 

They are 1st in 10+ yard plays allowed at 13 total for the season against teams with winning records.  UW had 13 plays of at least 10 yards against IU. Their other 8 FBS opponents averaged 11 plays of at least 10 yards gained. 

They are conversely 134th in 10+ yard plays gained against teams with winning records with 7 such plays.  Against the other 8 FBS opponents they have averaged almost 18 such plays.  UW really slowed them down, as did scUM who only allowed them to have 8 plays of at least 10 yards.

For comparison OSU has 64 plays of 10+ yards against winning teams (16 per game) and has allowed 40 plays (10 per game) of 10+ yards against winning teams