Introduction 

Analyses

Average number of PhD candidates supervised 

We asked PhD holders how many other doctoral candidates were, on average, supervised simultaneously by their supervisor during the course of their doctoral training. Across all research fields, most respondents indicated that their supervisor typically supervised between 1 to 2 or 3 to 4 other PhD candidates in addition to themselves.

The figure below shows the distribution of the number of doctoral candidates supervised simultaneously by the same supervisor, according to the field of research. To facilitate interpretation, the numbers have been grouped into three categories: 0 to 2, 3 to 4, and 5 or more.

The analysis confirms the existence of a significant relationship between the field of research and the number of doctoral candidates supervised at the same time. Supervisors in the SSH appear to supervise fewer individuals, while those in ENS and LHS tend to work in larger groups, supervising more doctoral candidates in parallel.

Meetings with supervisors  

Frequency of meetings: We asked PhD holders (n = 836) about how often they met with their supervisor (either in person or remotely) to discuss their research project. The responses show wide variation: some met with their supervisor several times a week (n = 178), while others had contact only once a month (n = 156), or even less frequently (n = 168). 

When examining the frequency of meetings by field of research, it appears that PhD candidates in the SSH have less frequent interactions with their supervisors compared to those in other disciplines. While nearly half of the candidates in ENS and LHS reported meeting them at least once a week, 60% of PhD candidates in SSH stated that they had contact only once a month or even less frequently.

Match between meeting frequency and expectations: The literature highlights the importance of alignment between the support PhD candidates expect and the support they actually receive. Mismatched support, whether perceived as insufficient or inappropriate, is often linked to feelings of dissatisfaction (Pyhältö, Vekkaila, & Keskinen, 2015). For example, a monthly meeting with a supervisor may feel sufficient if it meets a candidate’s expectations, but may seem too infrequent if more guidance is desired or, conversely, too frequent if the candidate seeks greater autonomy. This is why we asked PhD holders whether the frequency of meetings matched what they had hoped for. The results show that, for the vast majority, the frequency of meetings met their expectations.

Among the 144 individuals (17.3%) who expressed a desire for more frequent meetings with their supervisor, more than half (56.3%) reported meeting them only once a month or less. Only 13% of PhD candidates who met with their supervisor less than once a month said they were satisfied with that frequency.

Looking at the profile of these 144 individuals who wished for more frequent meetings, 52.8% were women. The majority came from the field of ENS (43.8%), followed by SSH (34%), and LHS (22%).

A logistic regression was conducted to identify the variables significantly associated with the likelihood of belonging to the group who met their supervisor “as often as they wanted,” as opposed to those who saw them less frequently. The analysis, controlling for gender, field of research, and meeting frequency (categorised into three levels: (1) high – at least once a week; (2) regular – once or twice a month; and (3) rare – less than once a month), revealed the following results:

• Meeting less than once a month ("rare") significantly reduced the likelihood of belonging to the “as often as I wanted” group (OR = 0.02; p < 0.001), compared to a high frequency (at least once a week).

• Regular meeting frequency (once or twice a month) also had a significantly negative effect on this likelihood (OR = 0.09; p < 0.001), compared to frequent meetings.

• Being in the SSH field increased the likelihood of belonging to the “as often as I wanted” group (OR = 2.53; p < 0.001), compared to those in NES.

These findings suggest that, across all research fields, aiming for at least one meeting per month with the supervisor may be beneficial, while still considering the specific expectations of the PhD candidate. It is also important to recognise that supervision needs can vary by discipline and may evolve throughout the course of the doctorate—for example, a typically autonomous candidate may require more intensive support during the writing phase (McAlpine & McKinnon, 2013).

Support from the supervisor for the post-PhD phase 

We asked PhD holders about the support provided by their supervisor in preparing for the post-PhD phase. According to the results, 47.7% of them believe that their supervisor gave them useful advice for their professional future. However, support in building a career plan received the lowest level of agreement, with only 27.6% of respondents expressing a favorable opinion.

Satisfaction with the supervisor  

PhD holders were asked to assess their satisfaction with the guidance provided by their supervisor. Respondents rated their level of satisfaction on a five-point scale ranging from 1 = very dissatisfied to 5 = very satisfied. A significant proportion (79.9%) of PhD holders reported being (somewhat or very) satisfied with their supervisor’s guidance. This percentage varies little across different research fields. 

Relationship between meeting frequency and satisfaction with the supervisor: A positive relationship is observed between the frequency of meetings with the supervisor and the level of satisfaction among PhD holders. Those who report the highest levels of satisfaction are also those who benefited from regular supervision, with at least one meeting per week. Conversely, the proportion of satisfied individuals drops significantly when meeting frequency decreases from once a month (77.6%) to less than once a month (52.4%).

These results suggest that, in general, aiming for at least one meeting per month would help optimise the quality of doctoral supervision. However, it is also important to note that the ideal meeting frequency may vary depending on individual needs, the stage of progress in the project, or the disciplinary context. Adopting a flexible, project- and student-centered approach would therefore help maximise the relevance and effectiveness of supervisory interactions.

Daily supervision work

We asked PhD holders whether their supervisor was the person who provided their day-to-day supervision during their doctoral studies. Among the respondents (n = 837), 30.2% stated that their supervisor was not the person responsible for their daily supervision. This number changes from 25.9% for the PhD holders in the SSH to 35.7% among PhD holders in LHS, the latter having the highest percentage. This difference may be explained by the structure of large research teams, where daily supervision is shared with other members of the laboratory, such as postdocs or research coordinators. 

Role of the mentor during PhD

In the survey, a mentor was defined as “an experienced person who guides, advises, and supports you in times of doubt or failure in order to foster your career development.” Respondents were then asked to identify the person or people who played this role during their PhD and/or in the period following their dissertation defense. For this question, participants could select multiple responses. 

Among the PhD holders who responded to this question (n = 1,156), just over half (54.5%) identified their primary supervisor as a mentor, while 20.9% mentioned their co-supervisor. Notably, 241 individuals (20.9%) reported not having a mentor. Among those who selected the “other” category, the most frequently mentioned group was a family member. 

Role of the supervisory committee

While individual supervision relationships remain a key factor in the success of a PhD, the use of supervisory committees, promoting collaboration among multiple supervisors who offer complementary input, has become increasingly formalised over the years (Pyhältö, Tikkanen, & Anttila, 2024). In the WBF (French-speaking part of Belgium), the supervisory committee reflects this collaborative dynamic. It consists of the primary supervisor and at least two members holding a PhD degree. Its mission is to guide the PhD candidate in shaping their research direction, expanding their academic network, and contributing to the development of their training program. Committee members commit to regular follow-up and ongoing dialogue throughout the doctoral journey. Moreover, university regulations explicitly state that the committee must meet "at least once a year."

Meeting frequency: We asked PhD holders (n = 836) about the frequency of their meetings (in person or online) with their supervisory committee to discuss their research project. More than half reported meeting their committee "once a year." However, 5.5% stated they had never met with their committee, and for 28.8% of respondents, meetings occurred "less than once a year."

The frequency of meetings with the advisory committee varies by field of research. PhD candidates in LHS tend to interact more regularly with their committees than those in other disciplines. Specifically, 41.7% of respondents in ENS, and 36.7% in SSH, reported meeting their committee less than once a year, or never, compared to only 18.9% of those in LHS.

These findings are concerning. Although all university regulations stipulate that at least one meeting per year is required, the data show that this rule is not consistently followed in practice. It is therefore essential to reinforce the regularity of the supervisory committee meetings, given the low meeting frequency reported by some PhD holders.

Usefulness of the supervisory committee: We asked PhD holders (n = 836) whether their supervisory committee was helpful in advancing their research throughout their doctoral studies. For 36.6% of PhD holders, the committee was not (not at all or not very) useful. This percentage rises to 43% for PhD holders in ENS fields, compared to 31.5% in LHS and 32% in SSH. 

Relationship between meeting frequency and perceived usefulness of the supervisory committee: A positive relationship is observed between the frequency of meetings with the supervisory committee and the perception of its usefulness. Individuals who consider their committee to be useful are also those who meet with it more regularly, at least once a year. These findings suggest that, as a general rule, aiming for at least one annual meeting with the committee would be beneficial in order to maximise its contribution to the doctoral journey. 

Cross-sectional analysis: Satisfaction with the supervisor

It is relevant to examine the variables that may influence PhD holders’ level of satisfaction with their supervisor. Is it the frequency of meetings? The support provided for the post-PhD transition? The number of doctoral candidates supervised? Or are certain research fields associated with higher perceived supervision?

To answer these questions and identify the factors correlated with the likelihood of belonging to the group of PhD holders who reported being “very satisfied” with their advisor’s supervision (48.4%), logistic regression models were used. The “backward stepwise” selection strategy was used, allowing for the identification of the most relevant variables for the model.The analysis was conducted in steps:

• Step 1 – Demographic variables: gender (female = 1), age, and nationality (Belgian = 1).

• Step 2 – PhD-related variables: broad field of research (SSH, LHS, reference category: ENS), number of years since obtaining the PhD, duration of the PhD, and whether the person received funding during the PhD (yes = 1).

• Step 3 – Supervision-related variables: frequency of meetings with the supervisor(regular, rare; reference category: frequent), satisfaction with that frequency (yes = 1), number of doctoral candidates supervised (5 or more; 3–4; reference: 0–2), whether the advisor provided day-to-day supervision (yes = 1), whether they were considered a mentor (yes = 1), and the average of three items measuring post-PhD support (see here).

The final model provided a statistically significant improvement over the model with only the constant term, χ²(8) = 288.59, p < .001. The model’s goodness-of-fit, as indicated by Nagelkerke’s pseudo R², was 0.43 (Cox and Snell = 0.32). The table below presents the final model that was retained.

The regression analysis reveals that, all else being equal, several factors influence the likelihood of a doctoral candidate reporting being “very satisfied” with the supervision received from their advisor:

• Being of Belgian nationality significantly reduces this likelihood.

• The number of years spent completing the PhD significantly lowers the probability of being very satisfied.

• The frequency of meetings with the advisor also plays an important role. Doctoral candidates who meet with their advisor rarely or occasionally are less likely to report being completely satisfied compared to those who meet frequently.

• Furthermore, satisfaction with the frequency of these meetings is a key factor: individuals who report having met with their advisor as often as they wished are much more likely to be in the group of “very satisfied” doctoral students.

• In addition, the supervisor's involvement in day-to-day supervision is a positive factor that increases the probability of being very satisfied.

• Lastly, doctoral candidates who perceive active support for their professional future after the PhD are more likely to report being very satisfied.

The graph above provides a more visual illustration of which variables are associated with satisfaction regarding the supervisor, as well as the degree of certainty of these results. The squares represent the effect of each variable on satisfaction. The horizontal bars correspond to the confidence intervals, i.e., the degree of precision of the estimate. The vertical reference line, placed at 1, indicates the absence of effect. If the confidence interval includes 1 and therefore crosses the line, this means that the effect of the variable is not statistically significant. The odds ratio (OR) compares the likelihood of being satisfied between two groups:

• An OR of 1 means that satisfaction is equally likely in both groups (“very satisfied” vs. “others”).

• An OR greater than 1 indicates that the study group (e.g., doctoral students satisfied with the frequency of meetings) is more likely to be very satisfied than the reference group (e.g., doctoral students dissatisfied with the frequency of meetings).

• An OR below 1, on the contrary, indicates that the study group (e.g., infrequent supervision) is less likely to be very satisfied than the reference group (e.g., frequent supervision).

In summary, doctoral candidates’ satisfaction appears to be strongly linked to the concrete involvement of their supervisors, both in terms of time (meeting frequency, regularity, presence for daily supervision) and support, especially regarding their post-PhD career path. The most striking factor is satisfaction with the frequency of meetings: it is not just the objective frequency that matters, but above all the doctoral candidates’ positive perception of it. It is worth noting that no significant effect was observed for the number of doctoral candidates supervised. And finally, it is important to emphasise that this type of analysis allows for the identification of correlations between variables, but not causal relationships.