Research
Those who wish to deny the impact of technology in learning often claim that there is no evidence that it improves learning. They point to the absence of research studies.
This absence of research is because technology never acts alone to improve learning, except in a few tightly defined circumstances such as exam revision. It is always the combination of technology and pedagogy that has the impact. As pedagogy is critically dependent on the nature of a school and its pupils, all being different, it is impossible to set up randomised controlled trials across several schools. You also cannot generalise; what works in one school may well not work in another without local tailoring.
This is also the reason why technology use cannot be linked to raised achievement. There are always other factors that could have been responsible where raised achievement is recorded. The question that must be asked is whether the overall changed pedagogy and attitudes of learners could have been achieved, or as easily achieved, had the use of technology not been a factor.
The kind of research that is possible is action research studies comparing teaching and learning without technology to the teaching and learning that results when technology is introduced and pedagogy changed, to take full advantage of the affordances of the technology. Such studies have been carried out by hundreds of schools and to their satisfaction have shown considerably improved learning and greater teacher effectiveness.
There have also been studies of the introduction of technology where pedagogy has not been changed. Not surprisingly these often show that little or no learning improvement has happened and that the investment in the technology has been wasted.