Although several companies developed tablets throughout the 1990s and 2000s, the tablet computer only became mainstream after Apple introduced the iPad in 2010. Later that year, Samsung released the Galaxy Tab, the first tablet to run Google's Android operating system. Like the iPad, Android tablets can run millions of different apps, making tablets a portable option for both work and play.
A null hypothesis is one that is assumed to be true unless it has been contradicted. It is used to compare to another hypothesis. The experimental hypothesis is what you are observing, and you expect it to differ from the control. erm i know that a null hypothesis is when nothing happens at all i think.
Research Hypothesis (H1) The research hypothesis (or hypotheses -- there may be more than one) is our working hypothesis -- our prediction, or what we expect to happen. It is also called the alternative hypothesis - because it is an alternative to the null hypothesis. Technically, the claim of the research hypothesis is that with respect to the outcome variable, our samples are from different populations (remember that population refers to the group from which the sample is drawn).