Question

Suppose you filed your taxes and received a small refund from the IRS. What would have been the impact on the refund amount if you had decreased the W-4 allowances for that tax year?

Answer 1

If you decreased your W4 allowances then more tax would be taken off your paycheque and the result would be that you would receive a larger refund which is a pleasant thing to happen and ensures that you will not have to pay more taxes and represents a little savings also.

Answer 2

the refund amount will have increased.
w-4 is the form that you signed so your employer could withdraw a portion of your payment to be alocated to federal income tax. The fewer W-4 allowances you take, the more is withheld from your paycheck for tax purposes because the amount of tax payment that you have to pay is also increasing.