d = 0.34
Effect on objective competence (PSM)
d = 0.64
Effect on self-assessment (PSM)
17.9%
of progression effect mediated by thesis
d = 0.06
Graduiertenkolleg effect (n.s.)

A debated tradition

60 % of practicing physicians in Germany hold a doctoral degree. Yet the Wissenschaftsrat has described the thesis as frequently falling short of academic standards.

Propensity score matching: the thesis effect, isolated

After matching, 262 thesis–control pairs were balanced on all three matching variables.

The thesis is associated with a real but moderate gain in knowledge, paired with a disproportionate boost in confidence.

Propensity score matching: matched comparison

Mean scores after 1:1 nearest-neighbour matching. 262 matched pairs.

What kind of competence does the thesis build?

The largest effects emerge in research ethics (d = 0.68) and study design (d = 0.67) — the methodological core of scientific work.

Competency test subscale profile by promotion status

Mean ± SEM scores across 5 subscales. Started thesis n = 470, aspiring n = 915, none/undecided n = 221.

Domain matters: experimental theses outperform clinical ones

Experimental thesis holders score significantly higher on research practice than clinical-conservative ones (Δ = 0.71, p < 0.001).

Subscale scores by doctoral domain

Mean scores per 5-item subscale. Experimental n = 207, clinical-conservative n = 183, clinical-surgical n = 77.

The thesis explains 18 % — but only 18 % — of the progression effect

The doctoral thesis mediates 17.9 % of the total effect of academic progression on objective competence.

The thesis is one of several pathways to scientific competence, not the dominant one.

The null findings: structure does not save the thesis

Neither structured doctoral programmes nor supervision satisfaction predict objective competence.

The doctoral thesis enhances competence — but the effect depends on what kind of research is done.

Beliefs and reality: the experience-induced realism

Aspiring students believe more strongly in salary and career benefits than students with thesis experience (d = 0.47).

Beliefs about doctoral thesis value by promotion status

Likert scale (1 = fully agree, 5 = fully disagree). Lower values = stronger belief.

Three principal findings

d = 0.34
The thesis works

After PSM, students with a started thesis score 1.34 points higher.

+1.5 pts
Domain matters

Experimental theses yield higher scores than clinical theses.

17.9 %
Mediation

17.9 % of the progression effect is mediated by the thesis.

The doctoral thesis remains meaningful — but it cannot bear the full weight of curricular preparation.