Assume that reading levels in a school district had been steadily declining over a period of years and that a new reading program was implemented to counter the trend

Statistics Nov 11, 2020

Assume that reading levels in a school district had been steadily declining over a period of years and that a new reading program was implemented to counter the trend. After two years, reading levels declined again, but the superintendent announced that the reading program was a success because reading levels would have declined even more without the program. What would be necessary to evaluate the validity of such an interpretation?