To follow on from oggers we are in the danger of fiddling with detail but with little gain. I'm not a fan of the various AofA gizmos either and to be frank I find them a bloody irritating distraction. The fans of these things become infatuated by them. Power plus attitude is equally of value whether during the climb out or on the approach just as much as it is in the cruise. If you are too slow the controls will be sloppy - take heed. Adding airspeed arbitrarily should be avoided always because at some point you will need to land. Using the formal standard 1.3 the stall is already a safe speed to use for a particular weight but controllability is also important and using the POH approach figures, which will normally be well above that, is more than enough. There can be no case for adding to the POH speeds for turbulence, this suggestion is wrong and foolish in my view.
Using the 1978 172N POH figures, the Performance Specifications figures give the stall: zero flaps 50kts CAS and with 40 degrees of flap 44 kts CAS. At these speeds the IAS is 9 kts higher according to the airspeed calibration table. However between 60 - 90 kts the CAS/IAS is mostly the same or varying to a maximum of just 2 kts. In line with most light aircraft the variation in CAS/IAS for approach speeds is inconsequential.
The Cessna 172N recommended approach speeds are: flaps up 60-70 KIAS, 40 degrees flap 55-65 KIAS. For Short field they recommend 60 KIAS. At these speeds the CAS and IAS are the same both on the approach and of course the climbout. It is worth noting, as its been mentioned, that the stall speed can vary by 5 KIAS between the most forward CG and the most rearward CG permitted for this aeroplane.