ETdA observation tools

Observation tools can be defined as a set of tools used to perform the data collection. In the ETdA model, different observation tools were used: a questionnaire, an evaluation form and direct and indirect observations (ergonomic checklist) for Clients, Professionals and Analyst dimensions (Table 4.3).

Table 4.3. ETdA observation tools.

Dimension Observation tool

Clients Questionnaire Professionals Evaluation forms Analyst Direct and indirect observation

Professionals and Analyst observation tools were defined as in the Ergonomic Workplace Analysis, EWA (Ahoen et al., 1999), and were correctly adapted to be applied in ETdA model.

EWA methodology allows a systematic and careful description of the task or workplace and has been planned to serve as a tool to help the Analyst to form a foundation of the work situation.

According to Hakkarainen, Ketola, and Nevala (2011), EWA is suitable for observing the ergonomics of sedentary, standing and physically active work. Due to its simplicity, its guidelines were used to help the Analyst and Professionals in the ergonomic factors’ assessments. To complete the tridimensional analysis, a questionnaire was developed and validated for Clients’

dimension.

4.2.2.1. Analyst dimension: ergonomic check list

Direct (directly in real work conditions with particular attention to the interrelations AP an CP) and indirect (video recordings or photographic material) observations, “auto-confrontation” interviews (Mollo and Falzon, 2004) with supervisors, professionals and safety staff, and simple measure devices, were used by the Analyst, providing the necessary information to characterize certain aspects of professionals activities and the way they interrelate with Clients. Reliable background data, available from the records of the organization were also collected. In order to help the ergonomic factors evaluation, Analyst used the EWA guidelines (Ahoen et al., 1989).

Through a general checklist with criteria for ergonomic evaluation, the Analyst rated the ergonomic factors using a 4-point scale representing health risks (Annex 1). A rating of (1) indicated a negative evaluation representing a critical situation with no health risk to the user population of the common area; (2) represented an acceptable situation but with suggestions to be implemented and, (3) was related to a positive evaluation with not relevant risk. At this point, it was important to mention that not only the workplace was under analysis but also Clients’

attendance in the area. If a situation representing health risk to Clients or Professionals were identified, the Analyst should immediately reported it to the Manager, and work should not continue, until that situation was properly evaluated.

Analyst defined the area for analysis according to work organization. In order to achieve this issue, a general description of CP interaction was also done. Potential risk situations to Clients were identified and evaluated. Two situations were identified:

If Professionals’ activities were developed across the common area then the ergonomic analysis should be performed according to the Professionals’ activities that provide a CP interaction. Examples illustrated in Figure 4.6 colour this idea. As it is possible to see, Professionals’ activities, identified as PA1 and PA2 are developed across the common area providing a CP interaction in several points within the area. In this case, the analysis must be done considering Professionals’ activities and CP interaction (Figure 4.6a);

If Professionals’ activities were developed in a particular area and the interaction CP is limited to that area then common area should be divided into sections. In this case, Analyst must ensure that a proper identification of the Professionals’ activity was done (Figure 4.6b).

a) b)

Figure 4.6. Definition of the analysis according to a) common area or b) Professionals’ activities.

4.2.2.2. Professionals dimension: evaluation form

Professionals used the evaluation forms to carry out the assessments of the commercial area.

The Professionals’ evaluation form used in this case study is presented on Annex 2. As it is possible to observe, a code identification of the activity was placed in the front page of the evaluation form. The main purpose of this code was to identify the section were the Professionals developed their activities. This way, the Analyst could associate if necessary a critical situation to the Professionals activities.

The form was a simple sheet on which Professionals marked his/her evaluation of the EFs as very poor (- -), poor (-), fair (+), or good (++). Following the Hakkaraine et al. (2010) recommendations, a place in the evaluation form was provided, allowing Professionals to identify the critical situations related to the common area.

4.2.2.3. Clients’ dimension: ETdA questionnaire

A questionnaire was the observation tool used to collect data from Clients’ dimension. Three main steps were identified in the drawing up of the first version of the ETdA questionnaire: (1) development, (2) pretest and, (3) validation. This version was developed and pretested in the framework of the Master thesis (Loureiro, 2008) (Annex 3). Although the validation of the ETdA

questionnaire did not present a new statistical methodology, in order for it to be used accurately, and in the framework of the present thesis, this step was essential.

(1) ETdA questionnaire development

Deshaeis (1997) considered that, the only reliable way to measure the extent of Clients’

perception in relation to a particular issue was using a technique of direct observation. This technique should also be an extensive one. That is, focused on large groups such as clients, costumers, users, among others. Thus, it was possible to infer the results more accurately.

This type of tool is defined as a direct administration tool, which presents, as main advantage, the possibility to quantify a variety of data and consequent establishment of multiple correlations.

Previously to the development of the ETdA questionnaire, objectives to be achieved were defined.

ETdA questionnaire should allow, in one hand, the socio demographic characterization of the Clients dimension and, in other hand, the assessments of the ergonomic factors. It is expected from the ETdA questionnaire results, the identification of the reasons that might affect Clients’

wellbeing.

The ETdA questionnaire was divided in three major parts: (1) Clients’ characterization, (2) Clients’ ergonomic evaluation, and (3) open question (Hill and Hill, 2008).

In the first part, two groups of questions were identified:

Questions clients (Qc), Questions clients/store (Qcs).

The first one, Qc questions, was related to Clients’ socio-demographic characteristics. Variables such gender, age, qualifications and professional activity were used. In order to contextualize Clients on the ergonomic analysis, they were asked about their knowledge on ergonomics. The Qcs questions were related to service quality and reasons why Clients’ choose the establishment for shopping. Service quality was accessed through a set of multiple questions related to professionals’ kindness, cost/quality ratio and hospitality.

The second part consisted on the evaluation of Clients’ perceptions regarding the ergonomic factors. This evaluation was done through a set of ergonomic questions named clients’

ergonomic questions (Qe questions). This group of questions included noise, lighting quality, thermal environmental and accident risk EFs. The service balcony dimension and the height of the shelves were used as indicators for the evaluation of Clients’ postures and movements. The restrictiveness was also accessed through a question that evaluates the software efficiency when a Clients/Professionals interrelation is implicated. The existence of a question where Clients must evaluate the general appearance of the establishment, intended to focus their attention on

the commercial area. This question is named a filter question. Clients were also asked to express their opinion about the quality of the professional training and the physical effort regarding the Professionals activities. The group of questions used in the ETdA questionnaire, are presented in Table 4.4.

Table 4.4. Type of questions used on ETdA questionnaire.

Question Description

Questions client (Clients characterization)

Age Gender Profession Education level

Questions clients/store

Reason for choosing the store Regularity

Visited sections- Quality/price ratio

Clients’ ergonomic questions

Postures and movements Lightning quality Lifting

Noise problem

General physical activity Restrictiveness Decision making

General opinion about the commercial area Accident risk

Thermal environment

Work communication and personal contact

The evaluation of the ergonomic factors was done using a three to five-level scale (frequency, probability and opinion scales) (Loureiro, 2008).

In the third part it was set an open-ended question where Clients express their general opinion about the commercial area. Respondents could declare in their own words, what could be improved in the service provided. This issue is very importance for total quality management strategies as results can indicate if the establishment strategy is in line with Clients’ expectations.

It is expected that although the first version of the questionnaire was developed in the health sector, its use can be generalized. Probably, an adaptation to each type of business may be necessary. For instance, an adjustment of the areas’ specifically terminology might be required.

By Managers, Analyst or Professionals’ suggestions, questions relevant to the analysis could also be included. For instance, Managers may have wanted to use this questionnaire to do a further study concerning Clients’ complaints about the area.

(2) ETdA questionnaire pre-test

According to Khalid and Helander (2004) a questionnaire must be previously tested in order to be used in a survey. Pre-test is an important step as it allows seeing the questions’

appropriateness and whether the questions are correctly interpreted by the respondents (Hill and Hill, 2008). This step was developed in the framework of a Master thesis (Loureiro, 2008).

Results of the pre-test allowed the development of a final version of the ETdA questionnaire presented in Annex 3. This version was used as the starting point for the final version of ETdA questionnaire used in this study case.

(3) ETdA questionnaire validation

Dzissah et al. (2005) refer that a reliable survey questionnaire should be consistent in its successful measurements of a given phenomenon. The ETdA questionnaire validity, reliability and feasibility were tested following the standard guidelines for quality measurement psychometric properties evaluation of observation tools (Ribeiro, 1999).

Validity refers to whether an instrument measures what is designed to measure. There are different criterions of validity: construct validity, criterion related validity, construct and content validity (Vieira, Maia and Coimbra, 2007). The factorial structure of ETdA questionnaire was analyzed assessing the theoretical construct validity (Usher and Pajares, 2009). This approach originates a mathematical model from which factors are estimated. The ETdA validity construction was evaluated by performing a factor analysis, using principal axis extraction with orthogonal (Varimax) rotation method. The factorial analysis was conducted on the 12 items included in the ETdA questionnaire, the Qe questions. The decision to use a Varimax rotation was related to ETdA theoretical conceptualization (see section 3.1, Chapter 3), which assumes that the ergonomic factors are independent and can be analyzed separately. Therefore, it was used the Varimax rotation to maximizes the factors’ independence. In order to perform the factors’

extraction: scree plot interpretation, Kaiser criterions and ETdA theoretical framework, were considered. Although Kaiser’s criterions can overestimate the number of factors to retain, the other options above mentioned outline this issue. After the analysis was run, results were given in terms of the percentage of variance obtained, regarding the eigenvalues for each component.

According to Field (2009), validity is a necessary but not sufficient condition of a measure.

Reliability is another quality of measurement that accesses the ability of the measure, to produce the same results under the same conditions. To be valid, the instrument must be, firstly, reliable.

Nowadays, extent methods are used to access this measurement propriety. These methods include the internal consistency technique called Cronbach’s Alpha. This measure is the most common measure of scale reliability used in most researcher studies. However, the Cronbach’

guidelines should be used with caution mainly since the alpha value is related with the number of items considered in a questionnaire and when the measure scale is heterogeneous its value can underestimate the true reliability of the questionnaire (Maroco and Garcia-Marques, 2006).

Regarding the ETdA questionnaire validity, the reliability was assessed in terms of the internal consistency of the ETdA subscales. Chronbach’s alpha statistic measured the overall correlation between items within a scale (Bosman, 2008).

Additionally, the operational qualities or the feasibility of ETdA questionnaires were investigated considering the Clients response in all categories of the questions (Salaffi, 2006).

In order to perform a questionnaire validation sample size should be taken into consideration.

According to Pestana and Gageiro (2005), the sample size should have at least ten participants per variable (Equation 4.1).

N = 10K, if 5 < K < 15 (K = variables number and N = sample size) Eq(4.1) Regarding the validation of the ETdA questionnaire, this issue was considered as well as the Kaiser-Meyer-Olkin (KMO) statistic. KMO represents the ratio of the squared correlation between variables to the squared partial correlations between variables (Field, 2009) and it is currently used to measure the sampling adequacy. This statistics varies between 0 and 1 (Table 4.5).

Table 4.5. Values for sampling adequacy according to Kaiser-Meyer-Olkin statistics (KMO).

Adequacy Statistics value Mediocre [0.5, 0.7[

Good [0.7, 0.8[

Great [0.8, 0.9[

Excellent >= 0.9

Field (2009) recommends that KMO statistic should be greater than 0.5 as bare minimum. To access correlation variables it was used the statist from Barlett’s test of sphericity. According to this test, hypotheses are defined as follows:

H⁰: II = I vs. H¹: II 6= I (H⁰ be the correlation matrix and H¹ the identity matrix)

A significance test could mean that the correlations between all variable were significantly different from zero. Therefore, it is possible to have an identity matrix different from the correlation matrix. The obtained Barllet’ test of sphericity value should be less than 0.05 (Field, 2009).