HP provides a type of model name near the keyboard or screen, but this name or number is probably not sufficient to get proper support for your computer. These names or numbers often represent a series of many notebook computers that look similar, but have different options and parts.
Fundamentally, river sampling is a web-based convenience sample of opt-in participants that uses a quota sampling approach to build a study sample. The selection method is not probability based, and participants cannot be described as representing any larger defined population.
stratified sampling is a sampling method wherein the population is divided into several strata or categories and a sample is taken from each stratum this method is very efficient and it helps researchers get enough hints about specific groups in the population