Complex sentence: The fact that the OLSAT is easier and less expensive to administer than an IQ test, such as the Stanford Binet V, makes it more accessible, but, its accuracy at higher levels is less reliable than the Stanford Binet.
Split into simpler sentences: The fact that the OLSAT is easier and less expensive to administer than an IQ test, such as the Stanford Binet V, makes it more accessabile. But, its accuracy at higher levels is less reliable than the Stanford Binet.