Did I mention I have hunting dogs? They are of different ages, different breeds and different sizes. The viszla is agile, smart, and quick. The griffon is steady, tenacious and tough. The braque d'auvergne is plodding, strong and methodical. All are exceptional at finding birds and hunting them. But the route each took to get there was very different. Like students, the skill they possess, prior knowledge and a few intangibles like personality all contributed to how quick they could pick up new skills and a put them to use. With a classroom the differentiation can seem daunting with varying numbers of students but the result is progress. Some students pick up new information or skills at different rates for the same reason the pups did, prior knowledge and skills and the intangibles ( like what may be happening at home). As long as their are points along the way to get feedback, such as with formative assessments, the progress will come. And if the practice /formative matches how the end point should look, looks the summative should be a breeze! I don't use tennis balls to train my dogs to hunt birds as I wouldn't assess a students use of evidence to support a claim by having them simply search a word bank.