For interview-based qualitative research, a purposive approach to sampling is widely favoured over random or probability sampling techniques (Bryman 2008).
This method seeks to ensure a strong relationship of relevance between research questions and cases studied. Snowball sampling may be employed for populations where a sampling frame is absent. In this study, however, the population of schools is known and data on their relevant characteristics are readily accessible from the Department for Education and Skills Annual Schools Census. The richness of this dataset makes the construction of a sampling frame possible, which allows for theoretical sampling. Using the research questions identified by the original aims of the study, a sampling frame was constructed by identifying state maintained
schools in England that occupied a range of points on the scales of three variables commonly used as proxies for socio-economic background, ethnic diversity and inclusivity of disabled people: proportion of students claiming free school meals, percentage white British and percentage identified as having special educational needs (Hobbs and Vignoles 2009).
Once the sample had been identified, it was possible to determine a number of cases that would provide theoretical saturation. This involved calculating values for each of the three variables for all schools in the population and taking the mean average of each. Cases could then be selected on the basis of their conformity to or deviation from the norm in each measure of socio-economic diversity. Once a school had been identified as meeting the requirements of the purposive sample, an online document search yielded further information in the form of Ofsted reports and from these it was possible to construe a group of potential case studies that demonstrated breadth in characteristics including regional location, geographical setting, and size and nature of the communities they served, as well as the three key variables. This was also informed by considerations of accessibility, in that teachers with whom the organisations involved with the study had had previous contact were approached if their schools fell within the parameters of the sampling frame. The schools selected were therefore drawn from an opportunity sample, in that the widely acknowledged difficulty of gaining access to schools (Harrell et al.
2000) was overcome by drawing on professional relationships that were an asset of the study, but the ultimate sample was the result of purposive selection based on the criteria outlined above.
The next step was to make contact with head teachers by letter and follow-up telephone call, introducing both the researcher and the aims of the project and detailing exactly what would be expected of participants and the benefits and risks involved in their taking part. Access was then negotiated with a date set for the researcher to visit the school at the convenience of its staff and students, by which time consent forms for all participants were to have been completed.
The table below shows the schools that took part in the study (under pseudonyms for reasons of confidentiality) after being selected to provide pupils from a diverse range of ethnic, special needs and socio-economic backgrounds. Data were derived from the 2008 DCSF census, and used to measure socio-economic deprivation (percentage of children taking free school meals - FSM), levels of special educational needs (SEN), and proportions of ethnic minority.
Northern Academy opened in 2007. Students and almost all staff transferred from the predecessor school. It has a specialism in citizenship with enterprise and is an average-sized secondary school. It serves an area of very considerable social and economic disadvantage. The town it serves has one of the highest rates of unemployment in the country. Around a third of the population is recorded as of Black or ethnic minority origin (BME) and over half of the BME population is unemployed. Some of the school’s pupils are from some of the most deprived areas in Europe. The proportion of pupils eligible for free school meals is well above average. About two thirds of the pupils are White British, the second largest ethnic group is Pakistani, and a small number of pupils are refugees or asylum seekers.
About a quarter of the pupils speak English as an additional language. The proportion of pupils with special educational needs and/or disabilities is above average and special provision is made for twenty-five physically disabled learners, some of whom are profoundly disabled. As a consequence, the percentage of pupils with statements of special educational needs is more than twice the national average. There is also a higher than usual number of looked after children on roll. It was judged to be a satisfactory school by Ofsted in 2010.
East Coast College is a larger than average secondary school near an industrial town. The BME population of the county is very small but more concentrated near the town. Unemployment is above average. The proportion of students with special educational needs and/or disabilities and those with a statement of special educational needs is above average and the majority of students are classified as White British, with other ethnicities making up only 5%. A lower than average number of children claim free school meals. Overall attainment is average. Ofsted judged the overall effectiveness of the school to be good in 2010.
Pupil Headcount % FSM % SEN
% White British
Northern Academy 905 34% 38% 66%
East Coast College 1,178 5% 23% 95%
Midlands Community 1,523 4% 21% 59%
South East High 997 5% 10% 80%
Hilltop School 87 20% 100% -
North West School 938 5% 20% 98%
Midlands Community School is a larger than average sized comprehensive school serving suburban and central areas of a small city. About a quarter of the town’s population is classified as BME and its unemployment rate is average. The proportion of students with learning difficulties and/or disabilities is below the national average and attainment on entry is above average. 60% of students are of White British background, and other pupils are from a variety of ethnic backgrounds, including Indian (16%) and Pakistani (12%).The proportion of students with English as a second language is higher than the national average. It is a high-achieving school with attendance well above the national average. Its overall effectiveness was rated outstanding by Ofsted in 2007. The researcher is a former pupil.
South East High School is an average sized school situated in a town on the south east coast of England. Unemployment is below the national average. The town’s population is nearly 95% white and one of the oldest populations in the country.
Less than 20% of the school’s pupils are from minority ethnic backgrounds and for about half of these pupils, English is not the first language. A lower than average proportion of pupis has learning difficulties and/or disabilities. Overall attainment is above average. It was categorised as a good school by Ofsted in 2008.
Hilltop School is a community special school in the North of England with 87 pupils on roll. All students have special educational needs in the form of severe or profound and multiple learning difficulties. Almost all pupils are of White British heritage. A small proportion of pupils are in the care of the local authority and 20%
receive free school meals. It was rated a good school by Ofsted in 2010.
North West School is situated in a village near the Scottish border, close to its county town. Only around 5% of the town’s population is classified as BME, which is the highest proportion in the county. There is a high rate of hate crime per capita.
Unemployment is well above the national average. The school is of average size.
Most pupils travel to the school from the surrounding rural areas, some of which are isolated. A large proportion of pupils travel from the county town. Almost all pupils are of White British background and live in areas of mixed social advantage, although a number are affected by rural isolation and/or disadvantage. The number of pupils whose first language is not English is very small. The proportion of pupils entitled to free school meals is below average. The number of pupils with learning difficulties and/or disabilities is broadly average. The school was found to provide a
satisfactory level of education by Ofsted in 2008. The supervisor of the research
has had previous contact with the school.