Interislander Ferry

Ranking Score Explained

G'day, thanks for your interest in how we calculate an experience's ranking score. It's at the core of Rankers so I'm pleased you're curious.

The ranking score percentage is used to compare and sort experiences in ranking tables. It is not necessarily a direct measurement of the quality of a particular experience as rated by its customers. I've found it a useful tool to allow me to find the best experiences with confidence. But I've also found it important to read the customer reviews before making any final judgements!

We calculate an experience's ranking score using a multi-factor data model instead of a raw data average (mean). This model takes into account several important questions. For instance - is there a trusted body of reviews? What is the age of a review and is the review from a credible source?

Below you'll find details around some of the important factors that went into calculating the ranking score for Interislander Ferry.

If you have any questions or comments about our ranking score calculation please get in touch at info@rankers.co.nz. We don't believe this is perfect or complete so we're always interested in ways we might make improvements.

Cymen Crick

Rankers Owner

Valid Reviews

349 Valid Reviews

The Interislander Ferry experience has a total of 360 reviews. There are 349 valid reviews that are included when calculating the ranking score and 11 invalid reviews that are excluded from the calculation. Reviews can be excluded only when a reviewer is not verified or after an investigation by our team determines the reviewer is not genuine.

Below is the distribution of ratings for the 349 valid reviews:

Rating	Count
10/10	40	11%
9/10	81	23%
8/10	103	30%
7/10	62	18%
6/10	29	8%
5/10	16	5%
4/10	7	2%
3/10	5	1%
2/10	2	1%
1/10	4	1%

77.13% Average

The raw data average (mean) for all the Interislander Ferry valid reviews is 77.13% and is based on 349 valid reviews. This value is not used to calculate the ranking score and it only provided here as a comparison to the weighted average.

Face-to-Face Reviews

309 Face-to-Face Reviews

The Rankers team meets with travellers while they’re in New Zealand and conducts face-to-face surveys. These reviews, in our opinion, are the most trusted in the industry and represent a critical control sample. To our knowledge, we are the only travel review website in the world that has gone to this extent.

More about face-to-face reviews

Within the 349 valid reviews, the experience has 309 face-to-face reviews collected during interviews by our team.

Below is the distribution of ratings for the 309 face-to-face reviews:

Rating	Count
10/10	30	10%
9/10	70	23%
8/10	98	32%
7/10	58	19%
6/10	25	8%
5/10	15	5%
4/10	6	2%
3/10	4	1%
2/10	2	1%
1/10	1	0%

77.22% Average

The raw data average (mean) for all the Interislander Ferry face-to-face reviews is 77.22% and is based on 309 face-to-face reviews. This value is not used to calculate the ranking score and it only provided here for comparison purposes.

Weighted Average

73.56%

Rankers calculates a weighted mean as a base average on which we can improve. Individual review's ratings are given a weight based on several factors. The weight of a review determines the overall impact it'll have on the final weighted average.

Recent reviews have more weight as they are more relevant and reflect the experience as it currently operates. Over time reviews become less relevant and loose their impact on the ranking score.

Low rating reviews carry slightly less weight. This dampens the effect of very low ratings for every experience across the board. This is especially important when the experience has few reviews overall and a single negative rating can grossly mischaracterise an experience. Consistent poor reviews will still result in the experience receiving a comparitively low ranking score.

Credible sources provide reviews that can be trusted. If we have verified a reviewer is genuine via a face-to-face meeting then the review carries additional weight.

Reviewer	Rating	Age	Relative Weight
Rina	9/10	105 days	100%
edm	1/10	379 days	38%
Colin Barrow	9/10	440 days	90%
Pauline	6/10	593 days	70%
Megan	5/10	745 days	53%
Marjolaine Loitz	4/10	775 days	44%
Keli Knox	10/10	1110 days	35%
Yar	1/10	1324 days	8%
Pinocity	6/10	1689 days	5%
Helen Russell	10/10	1870 days	5%
NewZealander	10/10	2144 days	4%
Tommy Pickett	9/10	2967 days	3%
Tom Bennett	8/10	2971 days	3%
Jeny Smolders	9/10	2973 days	3%
Gregg Wagstaff	7/10	3198 days	2%
Lianne Ijlst	8/10	3226 days	2%
Samantha and Neis	8/10	3227 days	2%
Brandon Cassidy	7/10	3243 days	2%
Vic Baughen	9/10	3245 days	2%
Anders Frank	7/10	3249 days	2%
Dina Schurer	8/10	3250 days	2%
Kim Youngsub	9/10	3251 days	2%
DEBBIE LAMBERT	10/10	3255 days	2%
Gary Williams	8/10	3255 days	2%
Kimberley Gardien	8/10	3262 days	2%
Antoine	9/10	3283 days	2%
Judit Van lanen	9/10	3288 days	2%
Bjorn Nielsen	8/10	3290 days	2%
Joel Virtanen	9/10	3292 days	2%
Corbin Hure	7/10	3292 days	2%
Ron	6/10	3295 days	2%
Thomas Simeon	8/10	3295 days	2%
Suzannah Hill	8/10	3296 days	2%
Kallan Mrozek	9/10	3297 days	2%
Kees Mol	9/10	3301 days	2%
Kristal Lavender	10/10	3301 days	2%
Bastian Bley	9/10	3302 days	2%
Jasmine Rogers	3/10	3303 days	1%
Louis Nilsson	8/10	3307 days	2%
Tim	7/10	3307 days	2%
Jendrik	6/10	3307 days	2%
Katharina	7/10	3308 days	2%
Chris Valchero	9/10	3311 days	2%
Rulp Niet	8/10	3313 days	2%
Soeren Buchheister	9/10	3314 days	2%
Chas Bronson	8/10	3314 days	2%
Jakob Lovdahl	9/10	3316 days	2%
Alexandra Schmidt	10/10	3326 days	2%
Jade Williams	10/10	3327 days	2%
Sam Staines	10/10	3328 days	2%
Nickolas Jonkergouw	7/10	3332 days	2%
Kirsty Smith	10/10	3332 days	2%
Eva Hesse	10/10	3347 days	2%
celine gries	8/10	3347 days	2%
tinagermany111	8/10	3362 days	2%
Cassandra Geyer	8/10	3546 days	2%
Olivier Reculeau	8/10	3547 days	2%
Thomas Michel	5/10	3548 days	1%
Lisa Haedrich	5/10	3552 days	1%
Nadja Guiliani	8/10	3556 days	2%
Elbrich	8/10	3556 days	2%
Jamie Serieux	7/10	3559 days	2%
Adele Jacques	9/10	3560 days	2%
Daniel Weber	6/10	3562 days	1%
Emily Noyd	8/10	3564 days	2%
Aparna Gula	10/10	3565 days	2%
Sebastiaan	7/10	3567 days	1%
Andre	9/10	3568 days	2%
Benedikt Hang	7/10	3569 days	1%
Yannick	8/10	3569 days	2%
S Black	9/10	3570 days	2%
Paul Larauze	6/10	3573 days	1%
Florence	6/10	3574 days	1%
Sarah Kovacs	8/10	3575 days	2%
Frenziska Schmid	7/10	3577 days	1%
Maud Livolsi	7/10	3584 days	1%
Lewis Whittle	6/10	3586 days	1%
Lukas Seager	6/10	3586 days	1%
Andrea Tabaka	8/10	3593 days	2%
Tina Rust	8/10	3595 days	2%
Joel Papak	8/10	3597 days	2%
Clemence and Pedro	9/10	3598 days	2%
Doms Wahlelr	9/10	3600 days	2%
Josef Biller	8/10	3600 days	2%
Justine Hoffmann	8/10	3601 days	2%
Friederike East	7/10	3601 days	1%
Mark White	10/10	3602 days	2%
Briony	8/10	3605 days	1%
Gabriel Siibers	8/10	3605 days	1%
Henry Wichler	8/10	3606 days	1%
Kyle Johnson	9/10	3608 days	2%
Niels Wezenberg	7/10	3609 days	1%
John Hamilton	9/10	3609 days	2%
Brianna Burd	9/10	3609 days	2%
Jessica Ruhland	8/10	3610 days	1%
Stula Vladimir	10/10	3611 days	2%
Cosmo Hartuna	7/10	3613 days	1%
Roland Fischer	6/10	3613 days	1%
Ross Holmes	9/10	3614 days	1%
Tilman	9/10	3616 days	1%
Petru	7/10	3617 days	1%
Fero Saarinen	6/10	3618 days	1%
Lauren Thompson	8/10	3620 days	1%
Meilin	8/10	3623 days	1%
Jonas Hoerning	10/10	3627 days	1%
Vanesha Patel	6/10	3628 days	1%
Mauricio Daniele	9/10	3628 days	1%
Sara and Antoine	8/10	3630 days	1%
Clare Pickford	6/10	3630 days	1%
Daniel Hill	10/10	3631 days	1%
Moritz Braun	7/10	3647 days	1%
Grischa Rodust	8/10	3654 days	1%
Chalie Dotesek	9/10	3655 days	1%
Julien Lafeville	7/10	3659 days	1%
Julia Huesam	8/10	3659 days	1%
Alexandre	9/10	3663 days	1%
Kev Zarka	6/10	3664 days	1%
Markus Wabing	8/10	3667 days	1%
Gessica	6/10	3700 days	1%
Simon Quass	9/10	3704 days	1%
Barthelemy	7/10	3933 days	1%
Brita Topp	10/10	4276 days	0%
Laim Thompson	8/10	4276 days	0%
Adriana	10/10	4284 days	0%
Pavel Jarolimek	5/10	4284 days	0%
Leonie Moeller	6/10	4285 days	0%
Doreen Gendel	8/10	4286 days	0%
Carla Oyarzun	3/10	4289 days	0%
Paolo Cases	3/10	4289 days	0%
Wolfgang and Christine	8/10	4294 days	0%
Helen	8/10	4307 days	0%
Olivier Carval	9/10	4309 days	0%
Hirsch Svenja	9/10	4310 days	0%
Mahr Svenja	8/10	4310 days	0%
Anna Guzewiez	9/10	4326 days	0%
Pier Durand	8/10	4330 days	0%
Serena Poggioli	9/10	4330 days	0%
Wayne Schist	7/10	4330 days	0%
Margreth Lydie	5/10	4338 days	0%
Laura Pleumeekers	7/10	4352 days	0%
David Brooks	10/10	4355 days	0%
Adrien Godeloup	9/10	4364 days	0%
Bet Dreno	8/10	4365 days	0%
Joachim	1/10	4366 days	0%
Pioter Jurkowski	7/10	4366 days	0%
Thomas Roche	9/10	4368 days	0%
Brian	9/10	4427 days	1%
hendrik king	9/10	4550 days	1%
Kiki Wykstra	5/10	4660 days	1%
Galen Licht	4/10	4660 days	1%
Yu-Ti Chu	7/10	4663 days	1%
Ton Martens	7/10	4663 days	1%
Joshua Perry	8/10	4668 days	1%
Molly Ladd	8/10	4668 days	1%
Michael Nolan	9/10	4672 days	1%
Julian Roots	9/10	4672 days	1%
Florent Corino	9/10	4676 days	1%
Amiot Cyriane	7/10	4676 days	1%
Annika	7/10	4676 days	1%
Jonas Herrmann	7/10	4676 days	1%
Matthieu Daveou	8/10	4676 days	1%
Julien Panossian	6/10	4676 days	1%
Raoul Montestruer	5/10	4676 days	1%
Alessa Ndra	8/10	4682 days	1%
Bjorn Hedmark	5/10	4683 days	1%
Evyatar Tulipman	7/10	4685 days	1%
S Curry	10/10	4700 days	1%
Ingrid	9/10	4744 days	1%
Reinier Timmer	7/10	4744 days	1%
Moorman	8/10	4753 days	1%
Stefan Roth	9/10	4778 days	1%
David	9/10	4792 days	1%
kevindang	10/10	4945 days	1%
Ruben Kunze	4/10	5027 days	1%
Sebastian Hol	9/10	5033 days	1%
Dick Stewart	8/10	5042 days	1%
David Beaumont	9/10	5049 days	1%
Beyeler	10/10	5054 days	1%
Nikita Sue	9/10	5059 days	1%
Schweiger	10/10	5061 days	1%
Jan & Marian	10/10	5140 days	1%
Konny	9/10	5144 days	1%
Waldemar Schuler	8/10	5144 days	1%
jule	3/10	5158 days	1%
Jack Potman	8/10	5360 days	1%
Jon_and_Family	9/10	5372 days	1%
Walker	9/10	5375 days	1%
Andreas Blessing	10/10	5383 days	1%
Gema	7/10	5386 days	1%
Avry Fabrice	6/10	5391 days	1%
Diane Johnston	9/10	5396 days	1%
Javier Munoz	8/10	5396 days	1%
Ben Akin-Smith	8/10	5397 days	1%
K Wallis	9/10	5402 days	1%
khs	9/10	5403 days	1%
Emma Ducat	9/10	5403 days	1%
Mr and Mrs Lambert	8/10	5410 days	1%
Andrew Koster	7/10	5416 days	1%
Bakker	8/10	5416 days	1%
Kimberly St Louis	8/10	5417 days	1%
Roel Wesstra	8/10	5423 days	1%
Seifert	10/10	5423 days	1%
Derek Woodward	9/10	5425 days	1%
Fabi & Sabi	8/10	5426 days	1%
Rosey834	8/10	5493 days	1%
Pete & Chris	10/10	5693 days	1%
Tony Masters	9/10	5756 days	1%
Hershell	8/10	5760 days	1%
Mike Robinson	9/10	5761 days	1%
Brent S	2/10	5762 days	0%
Zara Leyden	9/10	5770 days	1%
Judith	7/10	5774 days	1%
anon	8/10	5775 days	1%
Pierre Pilon	8/10	5776 days	1%
Jenny Omb	1/10	5781 days	0%
Frei Urs	6/10	5782 days	1%
Bryan Keddie	9/10	5792 days	1%
Leanne Rogan	5/10	5792 days	1%
Joanne Clarke	8/10	5796 days	1%
Wolfgang G	9/10	5802 days	1%
Thomas Signes	7/10	5823 days	1%
menzel	10/10	5841 days	1%
graemeh1	9/10	5842 days	1%
klinger	10/10	5842 days	1%
gereldineb	8/10	5852 days	1%
jennyb	9/10	5856 days	1%
Frank de Voogd	8/10	5862 days	1%
Jean Paul Mesnage	9/10	5868 days	1%
Hansjoerg Ehrmann	5/10	5869 days	1%
Daniel Alonso	9/10	5870 days	1%
Nigel Petrie	9/10	5881 days	1%
Tracy & Peter Cassidy	8/10	5897 days	1%
miniappleses	8/10	5919 days	1%
Josie Boyle	7/10	6030 days	1%
JanneP	9/10	6100 days	1%
Mikey	9/10	6107 days	1%
SablotniD	7/10	6112 days	1%
WiebkeS	9/10	6118 days	1%
Tanya	5/10	6119 days	1%
Jan	6/10	6120 days	1%
Viola	8/10	6121 days	1%
RowanL	7/10	6122 days	1%
VickiEngland	8/10	6130 days	1%
TomC1	8/10	6135 days	1%
AndyK	9/10	6135 days	1%
TatiamT	9/10	6135 days	1%
GillianK	8/10	6137 days	1%
EelcoK	9/10	6137 days	1%
Michael	9/10	6141 days	1%
soccaplaya14	10/10	6142 days	1%
Eugene	7/10	6143 days	1%
John	6/10	6145 days	1%
Tony	8/10	6150 days	1%
Middleton	4/10	6151 days	1%
Elise	8/10	6153 days	1%
Marie	8/10	6153 days	1%
ThomasS1	10/10	6157 days	1%
RasmusB	4/10	6159 days	1%
Simon	8/10	6164 days	1%
Phil&Joe	10/10	6166 days	1%
Marcus	7/10	6167 days	1%
Andre	7/10	6168 days	1%
Iris	9/10	6170 days	1%
Carla	7/10	6170 days	1%
Sandra	8/10	6174 days	1%
Schaffluber	10/10	6175 days	1%
Hayley	5/10	6176 days	1%
Con	2/10	6220 days	0%
felix	7/10	6221 days	1%
melissa	10/10	6228 days	1%
John B	5/10	6230 days	1%
Gemma	7/10	6269 days	1%
Henry	7/10	6269 days	1%
Antonella	10/10	6277 days	1%
Michelle	8/10	6277 days	1%
Laura	7/10	6285 days	1%
Sarah	8/10	6300 days	1%
Katerina	7/10	6320 days	1%
Erin	3/10	6321 days	1%
Mike Knight	9/10	6341 days	1%
Bronagh Mcartan	8/10	6350 days	1%
Dave	8/10	6361 days	1%
fgregory	10/10	6365 days	1%
Rhea	6/10	6410 days	1%
Georgina Mulligan	8/10	6422 days	1%
Karen C	7/10	6434 days	1%
Edmund Hillstone	10/10	6451 days	1%
Toby	6/10	6474 days	1%
Jennifer Baulch	9/10	6478 days	1%
Susan	8/10	6482 days	1%
Hoetnagels	7/10	6485 days	1%
Alan Bellerby	8/10	6488 days	1%
Sanne Jonker	7/10	6489 days	1%
Renske Tehurne	8/10	6493 days	1%
Benjamin Krein	7/10	6493 days	1%
Anne and Derek	8/10	6494 days	1%
James Davies	7/10	6494 days	1%
Naomi Horton	8/10	6495 days	1%
Roger Repolusk	8/10	6499 days	1%
Tony Wicks	6/10	6499 days	1%
Nancy Dol	8/10	6499 days	1%
Kristine	10/10	6499 days	1%
Kathy Hawey	9/10	6501 days	1%
David Buckley	8/10	6502 days	1%
Lena1	6/10	6502 days	1%
John Woodrow	8/10	6503 days	1%
Carmen Dolny	10/10	6503 days	1%
Haemnerli	8/10	6507 days	1%
Carla	8/10	6514 days	1%
Jim Curley	8/10	6514 days	1%
paulonline	7/10	6520 days	1%
Bex	6/10	6529 days	1%
Jenny Hulsebosch	8/10	6530 days	1%
Melissa Steedman	8/10	6541 days	1%
Tim	7/10	6542 days	1%
Falk Seidel	7/10	6545 days	1%
Hans Olthof	8/10	6545 days	1%
Anu	9/10	6548 days	1%
Anneli	6/10	6550 days	1%
purplekat99	10/10	6558 days	1%
Connor	10/10	6571 days	1%
Ad	7/10	6571 days	1%
Ann Westmacott	5/10	6576 days	1%
Paul Cowie	8/10	6577 days	1%
Ewen Maclean	8/10	6577 days	1%
Sarah Wilton	5/10	6577 days	1%
Arend v Dyn	7/10	6579 days	1%
Linda	8/10	6583 days	1%
Fiona	7/10	6583 days	1%
Ann	7/10	6584 days	1%
ranker_584	9/10	6587 days	1%
Christine	7/10	6587 days	1%
Nina	9/10	6587 days	1%
Anthony	7/10	6592 days	1%
Tom Clements	7/10	6592 days	1%
ranker_46	8/10	6704 days	1%
Pat Brewster	8/10	6704 days	1%
FrankOosterwijk	6/10	6789 days	1%
Kim	8/10	6789 days	1%
Helen	7/10	6820 days	1%
Heather	9/10	6820 days	1%
Helene	9/10	6832 days	1%
John	7/10	6832 days	1%
Giancarlo	6/10	6832 days	1%
Annette	4/10	6856 days	1%
John	5/10	6856 days	1%
Duncan	9/10	6861 days	1%
Jen	4/10	6872 days	1%
Rolf	8/10	6880 days	1%

Adjustments

Several adjustments to the weighted average are added to improve relevancy and credibility. These adjustments apply equally to all experiences that meet the criteria.

Sample Size Adjustment

No Adjustment

A reasonable number of reviews are necessary in order for the average to be credible and for an experience to take a prime position within the ranking tables. As such, experiences with only a few reviews have a moderated score. This does not mean that the experience or the reviews can't be trusted. The Interislander Ferry experience has plenty of reviews and does not meet the criteria for any adjustment.

Recent Reviews Adjustment

-1.95% Adjustment

There may be an adjustment if this experience hasn't received any reviews within the last 42 days. However the Interislander Ferry experience does not meet the criteria for any adjustment.

In addition, an experience's ranking score may be adjusted for each day there is no new ranking. After 1 day the adjustment comes into effect. The maximum number of days that can be adjusted for is 200 days. Due to the seasonal nature of many businesses, this adjustment is applied dynamically throughout the year.

The Interislander Ferry experience has been adjusted for 96 days. Adjustments are according to the following table.

Days	Adjustment
…	…
93	-1.89%
94	-1.91%
95	-1.93%
96	-1.95%
97	-1.97%
98	-1.99%
99	-2.01%
…	…

Balancing Adjustment

6.14% Adjustment

Every experience's review score is adjusted to balance out the disproportional number of negative reviews that are contributed.

You won't be surprised to learn that disgruntled customers are more likely to leave a review than happy ones. They are motivated to share their experience and warn others. We consider this a good thing and it's why reading the reviews is important. However we've learned it can misrepresent the experience in a more overall sense.

We apply a balancing adjustment to counteract this effect and ensure the ranking score is a more fair representation of the experience. This adjustment is applied equally to all experiences.

Final Ranking Score

78%

The final ranking score once any adjustments, ratings, and rounding has been applied. This value is recalculated each day and a short rolling average is applied. Therefore it may not be precisely accurate based on the other values presented.