What is quality of experience (QoE or QoX)?
Quality of experience (QoE or QoX) is a measure of the overall level of a customer's satisfaction and experience with a product or service and the vendor that's providing that product or service. QoE is related to quality of service (QoS), although the two concepts are not the same.
The International Telecommunication Union (ITU) defines QoE as "the overall acceptability of an application or service, as perceived subjectively by the end-user." QoE is a measure used to help understand the individual experiences of actual users when they interact with an application or service. Thus, QoE takes the user's viewpoint while assessing the quality of a product or service. Most importantly, it aims to answer the question, "did this product or service deliver a sufficient or good experience to end users, and to what extent?"
In general, the QoE paradigm can be applied to any consumer- or customer-related business or service. It is often used to measure customer satisfaction in the information technology (IT) and consumer electronics sectors.
A real-world analogy of QoE can be made with the example of the quality of medical care provided to a patient. The experience can be evaluated in many ways, however, the most meaningful results of the care being provided are how long the patient lives and how well they feel. The former result is numerically quantifiable (years, months, days), but the latter result is not quantifiable. Even so, both factors are important and help to determine the patient's overall QoE. Regardless of how these factors are defined (broadly or narrowly), they -- and thus the QoE -- can profoundly affect the patient's life and ultimately impact the long-term success of the medical organization. That's why it is in the best interest of any enterprise to act early to maximize the QoE of its users or customers.
Factors affecting QoE
When delivering a product or service, many factors can affect customer experiences and the resulting QoE, including the following:
- User-friendliness and usability.
- User confidence.
For IT- or telecommunications-related products or services, factors such as available bandwidth, jitter, delay and packet loss rate can also affect customer satisfaction and QoE. Examples of such services include cloud computing, telecommunications, video streaming, multimedia and networking.
Environmental variables, such as the user's working environment and hardware can also influence QoE. For example, the method being used (e.g., landline, cordless or mobile phone) to access or use the product can be a factor. The type of network being used may also affect QoE, as experiences can vary significantly if a free public network that's prone to delays and buffering is being used rather than a high-speed enterprise LAN.
The importance of the application to the user can also affect the QoE. For example, expectations and QoE results may be different if the user is using an application for personal use rather than using a business application to get work done.
How QoE is measured
Organizations have many ways to measure and evaluate QoE. The most common and subjective method is to poll or sample a large number of customers. For example, providers may ask users to rate the product or service quality on a fixed scoring scale, such as from 5 to 1, where 5 means the best quality and 1 indicates the worst quality. The numbers 2 to 4 may indicate poor, fair and good quality. Based on the responses from all polled users, the vendor calculates the mean opinion score (MOS).
MOS can be calculated in any situation where human opinions are useful and where there is a need to understand human subjective experiences. For example, the metric is commonly measured to assess the quality of VoIP calls and video sessions in call centers. Measuring MOS enables providers to identify quality issues that may be affecting user experiences and implement appropriate measures to eliminate the issues and improve experiences.
Machine learning-driven QoE
Tools that use machine learning (ML) may be able to automatically identify QoE issues and make suggestions on how to address those issues. Such tools may provide enhanced visualizations of the product or service so vendors can see where quality issues typically occur.
ML technology may also pinpoint or predict performance issues before they affect users or customers. Such early warnings may help providers to act proactively to improve user experiences from the outset.
QoE vs. QoS
QoS is a useful measure of the performance of a product or service, such as an IT network. It enables vendors or providers to understand performance gaps and then implement measures to address those gaps to help meet customer requirements. For example, an IT team may implement traffic shaping to improve the network's latency, reduce congestion and increase usable bandwidth for certain types of packets.
Generally speaking, QoS embodies the notion that hardware and software characteristics can be measured, improved and, in some cases, even guaranteed. In contrast, QoE measures how a user experiences a service. By taking the user's perspective instead of relying on the vendor's performance measurements, QoE expresses user satisfaction. Moreover, it does so both objectively and subjectively, so QoE is not always numerically quantifiable. Even so, it is one of the most significant factors in evaluating user experiences in the real world and using this understanding to improve the quality and performance of a product or service, often in conjunction with QoS.
In many situations, particularly in IT-related scenarios, vendors need to measure both QoS and QoE to improve their offerings and to meet customer expectations. QoE provides a high-level view of performance and quality from the customer's or user's perspective, while QoS provides more detailed and specific insights into individual performance parameters. Together, QoS and QoE provide a full picture of quality that vendors can use to assess the gap between where they are versus where they want to be to satisfy their users.