Methodological procedures used in both the pilot and final study Key issues to be addressed in this project are sampling (including gender, socio-

economic and cultural considerations), exclusion criteria and ethical considerations. Examples of the specific forms used in the study are given in the pilot or final study procedural sections.

Sampling

The most rigorous method of selecting a norm population is through stratified

random sampling. This is where the population is classified on variables such as age, sex, educational level, social class and race and then an appropriate percentage of participants is randomly chosen from each section (Gregory, 2004).

Ideally, for the findings of the research to apply to the population studied, the participants should be drawn randomly from the population. Without random sampling the external validity of the research is reduced and the findings are not generalizable to that population. However, practical difficulties mean that pure random sampling is not always possible (Bowling, 2009).

The sampling in this study was convenience or purposive sampling. That is, the participants were recruited from a known population that was easily accessible (Bowling 2009). The participants for the pilot study and the final study were recruited from primary schools near to where the researcher or the student researchers lived.

Socio-economic considerations

Many studies have linked lower socio-economic status to lower performance on standardised language tests (Spencer et al, 2016). Therefore, for the final study, it was important to gain a sample of participants from a wide range of socio-economic areas.

Schools were asked to provide information about the percentage of children who received free school meals in the school. The Free School Meal Entitlement (FSME) is a measure of low income but also provides a crude measure of socio-economic status (Hobbs and Vignoles, 2007). It is a proxy rather than a direct measure and is used frequently in educational research and policy. It is acknowledged that the FSME is not fully robust as it measures income only, does not recognise the changing eligibility for or past history of receiving FSM and does not take into account other aspects of deprivation (NIAR, 2010). However it is considered the best

proxy measure when compared to alternatives such as geographical deprivation indices (NIAR, 2010).

The national average of free school meal entitlement (FSME) in English schools in 2012 was 19.3% in maintained nurseries and state funded primary schools and 16% in state funded secondary provision (DfE, 2012).

Exclusion criteria

As the study aimed to gain norms for British language comprehension, the children required for the study were typically-developing children whose first language was English. Children with significant special needs (eg children with a statement of Special Educational Needs), those receiving Speech and Language Therapy (SLT) input and those whose first language was not English were excluded from both the pilot and final study. A statement of Special Educational Needs is an English formal educational documentthat details a child’s learning difficulties and the help that he or she will be given. It was replaced by the Education, Health and Care Plan (EHCP) in September 2014. Norbury (2004) included only native British English speakers who had no disorders of language and cognition and were not receiving any special educational support in her idiom pilot study to collect idiom norms. Huber-Okrainec et al (2005) excluded children who had a diagnosis of language disorder, a

requirement for special educational services or who were educated in a language other than English, in their study of idiom comprehension. Cain et al (2009)

excluded children who had a statement of special educational needs and whose first language was not English from their idiom study on 40 children in the North West of England.

Bishop (1997) warns that there is a danger of missing important information about cause and effect when applying exclusion criteria. However, she supports the careful use of exclusion criteria in research to ensure that an appropriate sample of the selected population is being tested.Children who were getting some extra support with literacy or numeracy on ‘school action’ or ‘school action plus’ (which are the steps below a statement of educational need) were included in the current study to prevent a population bias in favour of more able children only.

2.4.4.1 Ethical considerations

All studies should be carried out within an appropriate ethical framework to protect the participants and the researchers from potential harm and to make the research findings more robust (Stokes and Wall, 2014). Accepted research practices and codes of conduct must be followed. The British Psychological Society (BPS) Code of Human Research Ethics (BPS, 2014) describes some of the main ethical

considerations in research projects as obtaining informed consent from the

participants, ensuring and safeguarding confidentiality of data and the anonymity of the participants, and respecting privacy. The BPS also outlines the four main general ethical principles to be adhered to as: being respectful, competent, responsible and behaving with integrity. The standards of conduct and professional behaviour from the professional and regulatory bodies were also adhered to. These are the Royal College of Speech and Language Therapists (RCSLT) and the Health and Care Professionals Council (HCPC).

The Manchester Metropolitan University (MMU) ethical guidelines were followed to ensure that all ethical principles were adhered to and the project received ethical approval from the university (see appendices iv and v).

Obtaining informed consent: Gaining informed consent is essential before any study can commence. This ensures that the participants’ rights will be protected during the data collection (Cresswell, 2014). In this research, schools’ Head Teachers or Special Needs Co-ordinators (SENCOs) were used as gatekeepers to allow access to the children in the schools. Gaining their permission to carry out the study in the school was the first step in the process. This was achieved by sending the Head Teacher an introductory letter explaining the study aims.

As both the pilot and final study involved child participants, parental consent was obtained (Neil, 2005). The school sent out information letters about the project to parents which included an opt-out consent form. Swanell (2014) points out that the human research ethics guidelines allow opt-out consent if the research is low risk (ie the only foreseeable risk is one of discomfort), of significant public benefit or involves a dataset so large that individual consent is impractical to obtain. The current research fits into the ‘low risk’ category. Parents were informed that even if they gave consent for their child to take part they could withdraw him or her from the study at any time.

Verbal assent was gained from the child prior to each assessment in school. The children were also informed at the beginning of the assessment (or before each section if it was felt appropriate for that child) that it was fine to answer ‘don’t know’ if they were unsure of an answer and that they could discontinue the

assessment and go back to class at any time. This was to minimise any anxiety they may have had about the assessment.

Safeguarding confidentiality of data: Completed scoring sheets contained only the child’s initials and year and month of birth. Each child was allocated a study number. This pseudo-anonymization was necessary as parents were given the option to

withdraw their child’s data at any time from the study. Each child therefore had to be traceable. Completed forms were kept in a secure, locked location. In the final study written permission was gained from a sub-set of randomly selected parents to audio record their child’s assessment session for purposes of moderation(appendix vi). These recordings were kept securely on a password protected computer.

Respecting privacy: This was more difficult to ensure in the school settings as space was very limited and the children sometimes needed to be assessed at a table in a school corridor or cloakroom. However, the children were not disclosing any personal or confidential information, so ensuring privacy during the assessments was not essential.