What Is a Sampling Frame?

The sampling frame is also called sampling frame and sampling structure, which refers to listing or ordering the number of overall units that can be selected as samples to determine the sampling scope and structure of the entire population. After the sampling frame is designed, the necessary number of units can be selected by lot or by using a random number table. Without a sampling frame, the probability of a sample unit cannot be calculated, and thus probability sampling cannot be performed.

A good sampling frame should be: complete without duplication.

Common sampling frames: university student roster, phone list in city yellow pages,

The sampling frame is also called the sampling structure or sampling structure. In fact, it refers to the order or arrangement of all sampling units (overall units) that can be selected as samples. This concept first appeared in agricultural sample surveys in the United States. They believe that after the overall target is determined, it is still relatively abstract. All the units that should be selected as candidates should be cataloged so that the names, addresses, and numbers of the units included in the overall implementation should be implemented in words. This can also ensure that the units are neither omitted nor repeatedly drawn.

In practice, the sampling structure has three forms.

1) Specific sampling structure

That is, the sampling units can be listed in the form of a list. Including directory structure, area structure, and directory area composite structure. The 20,000 student roster in the example is a directory structure. When performing cluster sampling, we will arrange the city residents according to their customary section positions as an alternative residential group, which is the regional structure. If we do not conduct a comprehensive survey of the selected residents, but select some residents, we need a resident roster, which becomes a composite structure.

2) Abstract sampling structure

That is, the sampling unit does not have a list but is open. As long as the survey conditions are met, it is an element in the sampling structure. For example, in a random retail survey of a buyer or consumer in a large retail mall, the sampling structure is abstract and implicit.

3) Phased sampling structure

When the segmented beech design is adopted, different sampling structures can be generated according to different sampling stages. ^[2]

1.Lost target

cut back

Sampling frames and sampling units are a pair of basic categories of sampling. The mapping population of the actual population whose units satisfy the condition of "there is a certain corresponding relationship with each unit of the actual population. With this correspondence, you can find a specific one or some units in the actual population." The overall unit is called the sampling unit.

In other words, a population containing all sampling units is called a sampling frame, and the units that make up a sampling frame are called sampling units.

In fact, in order to facilitate the implementation of sampling, it is necessary to have a catalogue list. Each catalogue item in this catalogue list has a certain corresponding relationship with each unit of the actual population. A specific unit or units in a population. The sampling frame is such an inventory list.

Sampling frames can come in various forms: lists, manuals, maps, data packages ... Because whatever form the sampling frame takes, after sampling, the investigator must be able to find a specific sampling unit based on the sampling frame. Therefore, the sampling frame must be in order, that is, the sampling units must be numbered and arranged in a certain order; the sampling units contained in the sampling frame must be no weight and no leakage, otherwise sampling errors will occur.

Sampling units not only refer to the catalog entries that make up the sampling frame, but also indicate the specific unit or units that correspond to the actual population of the catalog entry. Visually speaking, it is not only the shadow, but also the entity reflected by the shadow. Although the sample literature is silent on this, it is helpful for readers to remember this. In order to distinguish these two different meanings of sampling units, physical sampling units are also called sample units or sample points.

The sampling unit is not necessarily the smallest unit that makes up the populationthe basic unit. A sampling unit may contain one or some basic units, in the simplest case only one basic unit. In simple random sampling, the sampling unit is the basic unit; in the cluster sampling, the cluster is the sampling unit, and the cluster may contain a considerable number of basic units. For example, in a mobile phone survey, we selected a residential building. The building is a sampling unit, and each resident in the building is the basic unit.